Electric Relay
- Thread starter RockerGuy
- Start date
TrainingWheels
Well-known member
Lots of potential reasons for the buzzing. If you're lucky it could just be poorly grounded. Clean up the ground/negative of the relay and make sure it has a clean connection to ground. Otherwise...
1a) Not sure where you installed the relay. It could be too close to the alternator or ignition system -> inducing a current in the relay causing it to 'vibrate.' If this is the case then check by turning the lights/relay on without the engine running. If the buzzing isn't there when the engine isn't running then you just have a location problem: relocate the relay a far as you can from the cars alternator and ignition wiring.
1b) if you can't relocate the relay, you can try two things: cover the sides of the relay with thin sheet metal or put a capacitor in parallel across the relay coil terminals. By putting the relay in a thin metal (conducting) cage that is grounded you are blocking out as much inductive noise as possible, but this method is less likely to guarantee success since you can't fully (although you may not need to) wrap the relay in metal. The capacitor option is easier and in your case probably more effective (smooths out any electrical ripples) but you'll have to wait for shipping or go down to an electronics store. Let me know if you need a capacitor recommendation (give me the relay model number and any specs you have first).
3) if the above doesn't work, check that the voltage across the relay doesn't fall too low. Eg. a 12V relay typically becomes borderline operational at 8V and appears to repeatedly switch between on/off (too fast to see but probably hear). So if the voltage across the relay drops below that (or 10V for cheaper ones) make sure the relay is properly hooked up. Get out your multimeter and check how far the voltage drops or if it is repeatedly fluctuating while the car is running. Check the resistance/continuity of your system and make sure there aren't any shorts or improper connections. If the voltage is fluctuating and its not a location issue then you probably have a noisy alternator (sign it's 'dying'): although first check that the battery terminals are clean (not corroded) and likewise with the alternator wiring.
If none of the above works (although most likely it is just a location issue) then you have a faulty relay. If a relay gets too hot (don't mount it on the radiator or engine block
) or is driven by too high a voltage you can permanently damage/weaken the internals. Order new from an electronics shop or your original supplier. When items are produced by the thousands...a bad one slips through every once in a while.
1a) Not sure where you installed the relay. It could be too close to the alternator or ignition system -> inducing a current in the relay causing it to 'vibrate.' If this is the case then check by turning the lights/relay on without the engine running. If the buzzing isn't there when the engine isn't running then you just have a location problem: relocate the relay a far as you can from the cars alternator and ignition wiring.
1b) if you can't relocate the relay, you can try two things: cover the sides of the relay with thin sheet metal or put a capacitor in parallel across the relay coil terminals. By putting the relay in a thin metal (conducting) cage that is grounded you are blocking out as much inductive noise as possible, but this method is less likely to guarantee success since you can't fully (although you may not need to) wrap the relay in metal. The capacitor option is easier and in your case probably more effective (smooths out any electrical ripples) but you'll have to wait for shipping or go down to an electronics store. Let me know if you need a capacitor recommendation (give me the relay model number and any specs you have first).
3) if the above doesn't work, check that the voltage across the relay doesn't fall too low. Eg. a 12V relay typically becomes borderline operational at 8V and appears to repeatedly switch between on/off (too fast to see but probably hear). So if the voltage across the relay drops below that (or 10V for cheaper ones) make sure the relay is properly hooked up. Get out your multimeter and check how far the voltage drops or if it is repeatedly fluctuating while the car is running. Check the resistance/continuity of your system and make sure there aren't any shorts or improper connections. If the voltage is fluctuating and its not a location issue then you probably have a noisy alternator (sign it's 'dying'): although first check that the battery terminals are clean (not corroded) and likewise with the alternator wiring.
If none of the above works (although most likely it is just a location issue) then you have a faulty relay. If a relay gets too hot (don't mount it on the radiator or engine block
) or is driven by too high a voltage you can permanently damage/weaken the internals. Order new from an electronics shop or your original supplier. When items are produced by the thousands...a bad one slips through every once in a while.
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Thanks for such a detailed response, you did cover all the bases and you're rigbt about the capacitor. It just so happen that Hyundai uses a pulse to prolong the life of their halogen bulbs. That creates the buzzing sound.
Another question, if i ignore that sound is it bad for the relay or my HID system i installed?
BTW I just bave a 12v relay, 20-30A
Thx
Another question, if i ignore that sound is it bad for the relay or my HID system i installed?
BTW I just bave a 12v relay, 20-30A
Thx
TrainingWheels
Well-known member
Haha. The relay will survive but that's definitely a good way to shorten the life of your HIDs. What you are referring to by the pulses is known as PWM (pulse width modulation: e.g. if you pulse a 12V bulb on/off 2/3 per second (or millisecond) of the time then the bulb will see 8V effectively and be as bright as if it were powered directly by an 8V battery without pulses). It is a very efficient method of regulating power but in your case...detrimental.
I see 2 solutions:
1a) put a capacitor + flyback diode across the relay coils and hope that it doesn't smooth the ripple so much that it restricts the output current. I assume this will work since the HIDs are already of sufficient brightness. If this doesn't work, then try part b)
1b) if the HIDs aren't at full brightness then your relay is restricting current at the output. As such I think your simplest option with your current setup is to use a lower voltage triggered relay and the capacitor/diode combo.
*The triggering/activation voltage rating of your new relay can be determined by taking a multimeter DC voltage reading across the current relay coil wires/terminals. Assuming the PWM is fast enough the multimeter should display the average voltage seen...this is your new relays voltage. If you are getting a jumpy reading (the PWM is slow) then take the average of the highest and lowest reading.
2) use something else to trigger the relay. The coil portion of the relay doesn't consumes a negligible amount of power but you should be safe putting the coil portion in parallel with any other relay (make sure the relay output/HID wires don't connect with the other relays output). Alternatively if your fog lights are 12V EACH (probably) you can put the coil portion in parallel with one of them. If they are a lower voltage you can try it anyways but not necessarily guaranteed to work since the relay is rated for 12V (might work down to 9V). Although your fog lights will have to be on for your HIDs to also turn on.
3) build a 'pwm filter' like this guy did for his volvo
4) use a transistor (BJT or FET) to take a VERY low power reading when something else is on (your fuel pump, any other accessory, something that turns on with the car) and in turn it will turn your relay on. It's like a very flexible miniature relay that turns on your larger relay.
4) bypass everything and put a switch somewhere in your car that turns the relay on whenever you want. That way you can be stealthy and drive around without any headlights on as well.
I see 2 solutions:
1a) put a capacitor + flyback diode across the relay coils and hope that it doesn't smooth the ripple so much that it restricts the output current. I assume this will work since the HIDs are already of sufficient brightness. If this doesn't work, then try part b)
1b) if the HIDs aren't at full brightness then your relay is restricting current at the output. As such I think your simplest option with your current setup is to use a lower voltage triggered relay and the capacitor/diode combo.
*The triggering/activation voltage rating of your new relay can be determined by taking a multimeter DC voltage reading across the current relay coil wires/terminals. Assuming the PWM is fast enough the multimeter should display the average voltage seen...this is your new relays voltage. If you are getting a jumpy reading (the PWM is slow) then take the average of the highest and lowest reading.
2) use something else to trigger the relay. The coil portion of the relay doesn't consumes a negligible amount of power but you should be safe putting the coil portion in parallel with any other relay (make sure the relay output/HID wires don't connect with the other relays output). Alternatively if your fog lights are 12V EACH (probably) you can put the coil portion in parallel with one of them. If they are a lower voltage you can try it anyways but not necessarily guaranteed to work since the relay is rated for 12V (might work down to 9V). Although your fog lights will have to be on for your HIDs to also turn on.
3) build a 'pwm filter' like this guy did for his volvo
4) use a transistor (BJT or FET) to take a VERY low power reading when something else is on (your fuel pump, any other accessory, something that turns on with the car) and in turn it will turn your relay on. It's like a very flexible miniature relay that turns on your larger relay.
4) bypass everything and put a switch somewhere in your car that turns the relay on whenever you want. That way you can be stealthy and drive around without any headlights on as well.
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You sir, are a genius!!!
I've read about the Capacitor & diode trick. Care to elaborate specifically what that does? I know the capacitor retains charge, but what does the diode do?
My HIDs are not flickering. How will it shorten the life of the unit?
TrainingWheels
Well-known member
When HIDs initially turn on they draw a lot of power to initiate the electrical arc through xenon gas, which is what emits the light. Initiating the arc requires much more power than maintaining it does. The problem with PWM is that depending on the rate of the pulses, your HID system may be repeatedly initializing the arc (which is beyond its design) or compensating for the intermittent loss of power by drawing more power on average.....this can overheat components. Your ballast is actually designed to work at pulses of ~100kHz, and does so very well, but when you introduce an external pulse, you create power ripples in the system that it wasn't design to filter. Since the relay buzzing is audible, that implies it is within the human range of 20Hz - 20kHz. Since you described it as a buzz and not a high pitch squeal, that implies it's occurring at the lower audible range (closer to the lower frequencies).
Just because you don't see any flickering, doesn't mean it isn't working harder (drawing more power) to compensate. Not seeing it, and without me taking proper measurements, means that it's either just fine or working harder than it should. To be safe, and considering the cheap implementation price, it's worth the piece of mind.
Reading what I wrote before, ignore the diode in parallel idea, in this case it is better off in series with a proper capacitor (I was just making a few conclusions on my own without actually seeing your setup). The diode is more so to serve as long term protection, a one way electrical valve. Normally your halogen bulbs are connected to some control module, but instead you've replaced the original load (bulbs) with a very low power coil / relay. The relay in turn completes closes a seperate circuit through which your HID system can connect to the battery. To solve the buzzing/pulsing we add a capacitor in parallel with the relays coil. When we put the capacitor across the coil it will store energy during the on phase of the pulse and release energy during the off phase of the pulse. Unfortunately, because we don't know the design of the control module, the capacitor may alternatively discharge back into the control module and damage it. The one way valve property of the diode ensures the capacitor can only release its energy into the coil.
I'll recommend you a capacitor and diode with links you can order online from a supplier that delivers within 2 business days for $8 shipping (or if you give PM me your city/postal code I can check TheSource store inventory for you and see if anything there would work), but first I'll need a little more detail about the relay.
What is the model number and manufacturer? I can use this to look up the resistance of the coil.
OR
Using a multimeter, measure the resistance between the coil terminals for me
BONUS: if you can set your multimeter to measure frequency, tell me what frequency appears at the relays terminals. This will tell me how quickly Hyundai pulses the signal.
By knowing the coils resistance I can figure out the maximum size diode + capacitor you need. Telling me the frequency will let me narrow the selection of diodes and capacitor to the smallest ones necessary....although not necessary it'll save you a few dollars and be more compact.
Just because you don't see any flickering, doesn't mean it isn't working harder (drawing more power) to compensate. Not seeing it, and without me taking proper measurements, means that it's either just fine or working harder than it should. To be safe, and considering the cheap implementation price, it's worth the piece of mind.
Reading what I wrote before, ignore the diode in parallel idea, in this case it is better off in series with a proper capacitor (I was just making a few conclusions on my own without actually seeing your setup). The diode is more so to serve as long term protection, a one way electrical valve. Normally your halogen bulbs are connected to some control module, but instead you've replaced the original load (bulbs) with a very low power coil / relay. The relay in turn completes closes a seperate circuit through which your HID system can connect to the battery. To solve the buzzing/pulsing we add a capacitor in parallel with the relays coil. When we put the capacitor across the coil it will store energy during the on phase of the pulse and release energy during the off phase of the pulse. Unfortunately, because we don't know the design of the control module, the capacitor may alternatively discharge back into the control module and damage it. The one way valve property of the diode ensures the capacitor can only release its energy into the coil.
I'll recommend you a capacitor and diode with links you can order online from a supplier that delivers within 2 business days for $8 shipping (or if you give PM me your city/postal code I can check TheSource store inventory for you and see if anything there would work), but first I'll need a little more detail about the relay.
What is the model number and manufacturer? I can use this to look up the resistance of the coil.
OR
Using a multimeter, measure the resistance between the coil terminals for me
BONUS: if you can set your multimeter to measure frequency, tell me what frequency appears at the relays terminals. This will tell me how quickly Hyundai pulses the signal.
By knowing the coils resistance I can figure out the maximum size diode + capacitor you need. Telling me the frequency will let me narrow the selection of diodes and capacitor to the smallest ones necessary....although not necessary it'll save you a few dollars and be more compact.
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BONUS: if you can set your multimeter to measure frequency, tell me what frequency appears at the relays terminals. This will tell me how quickly Hyundai pulses the signal.
By knowing the coils resistance I can figure out the maximum size diode + capacitor you need. Telling me the frequency will let me narrow the selection of diodes and capacitor to the smallest ones necessary....although not necessary it'll save you a few dollars and be more compact.
Thanks for the response.
I have no clue how to measure frequency on a multimeter. But I will let you know the resistance when i get the chance.
Cheers
TrainingWheels
Well-known member
Shame, couldn't find a data sheet for that relay, but that is alright.
Alternative bonus: not necessary but it's an alternative way for me to figure out the frequency. If you can measure DC voltage, while the car is running, what is the voltage across the battery terminals and across the relay coil terminals.
I'll get back to you with diode + capacitor recommendations when I'm back home later tonight.
Alternative bonus: not necessary but it's an alternative way for me to figure out the frequency. If you can measure DC voltage, while the car is running, what is the voltage across the battery terminals and across the relay coil terminals.
I'll get back to you with diode + capacitor recommendations when I'm back home later tonight.
TrainingWheels
Well-known member
Please do.
I'm expecting you to tell me a coil terminal voltage reading of somewhere from 6-13V and battery voltage of 12-~14.5V
I'm expecting you to tell me a coil terminal voltage reading of somewhere from 6-13V and battery voltage of 12-~14.5V
So...
Coil voltage= 11.1
Battery v = 14.1
Another question, would you know if the PWN unit is located in the light housing or it is normally programmed in the main computer?
My light housing has several marker lights also, maybe I could use those as a trigger if they don't have the pulse. But I don't know how to tell if they have the pulse also.
I also detected yesterday that the ballast is getting warm in one of the lights, so I guess that's not good
I did a bit of reading and someone used a 4,700 uF capacitor
Coil voltage= 11.1
Battery v = 14.1
Another question, would you know if the PWN unit is located in the light housing or it is normally programmed in the main computer?
My light housing has several marker lights also, maybe I could use those as a trigger if they don't have the pulse. But I don't know how to tell if they have the pulse also.
I also detected yesterday that the ballast is getting warm in one of the lights, so I guess that's not good
I did a bit of reading and someone used a 4,700 uF capacitor
TrainingWheels
Well-known member
The PWM unit is 95% most likely in the main computer.
That's a good idea, anything that isn't PWMd will work for the trigger. Your relay only pulls 140mA to operate.
...........
Just ran the proper simulations.
Couldn't find the switching frequency online so use a worst case scenario (80Hz pulses from Volvo). And after calculating the parts.... you can't get them from TheSouce so here are the digikey links.
Resistor: 2.5+ ohm resistor. This will limit the surge current (start up current) that the capacitor draws to ~4.3A...since your headlight fuse is probably rated for 5A.
http://www.digikey.ca/product-detail/en/PNP300JR-73-2R7/2.7AECT-ND/2059185
(put the resistor in series either before or after the diode)
Capacitor: 4,700 uF will work. The noise will be reduced considerably, but ~20,000 uF will reduce the vibrations 5x in magnitube (...not sure how much quiter that would be sound wise though). Since there are other noises the car makes while on 4,700 uF should be fine. If you want though, you can order both sizes and use the larger one if you can still hear the noise. Without testing it's hard to tell is 4,700 uF would even be audible, but
4,700 uF: http://www.digikey.ca/product-detail/en/EGPA250ELL472MM30S/565-3383-ND/3528520
22,000 uF: http://www.digikey.ca/product-detail/en/ECO-S1EA223DA/P6591-ND/131411
If you care less about the buzz noise (because you already can't hear it when your hood is closed) and just want to make sure your relay is operating within spec: 500uF at a minimum will work. Regardless, 500 uF will still reduce the noise significantly from what you have now and it may not even be audible. How this translates into audible sound is hard to guess without testing.
680 uF: http://www.digikey.ca/product-detail/en/MAL214651681E3/4502PHBK-ND/2410367
If the buzzing doesn't bother you much now, and you only somewhat hear it when the hood is closed, I'd just go with the 680 uF. It is the small and will get the job done. Otherwise since they aren't to expensive, you can get the 22,000 uF as well and just see how much of a diference it makes.
(the negaticve arrows on the case of the capacitors point towards the negative leg)
Diode:
This will be plenty: http://www.digikey.ca/product-detail/en/1N4002/1N4002FSCT-ND/1532743
-------------------
From digikey you can checkout as a guest. $8 shipping flat rate.
That's a good idea, anything that isn't PWMd will work for the trigger. Your relay only pulls 140mA to operate.
...........
Just ran the proper simulations.
Couldn't find the switching frequency online so use a worst case scenario (80Hz pulses from Volvo). And after calculating the parts.... you can't get them from TheSouce so here are the digikey links.
Resistor: 2.5+ ohm resistor. This will limit the surge current (start up current) that the capacitor draws to ~4.3A...since your headlight fuse is probably rated for 5A.
http://www.digikey.ca/product-detail/en/PNP300JR-73-2R7/2.7AECT-ND/2059185
(put the resistor in series either before or after the diode)
Capacitor: 4,700 uF will work. The noise will be reduced considerably, but ~20,000 uF will reduce the vibrations 5x in magnitube (...not sure how much quiter that would be sound wise though). Since there are other noises the car makes while on 4,700 uF should be fine. If you want though, you can order both sizes and use the larger one if you can still hear the noise. Without testing it's hard to tell is 4,700 uF would even be audible, but
4,700 uF: http://www.digikey.ca/product-detail/en/EGPA250ELL472MM30S/565-3383-ND/3528520
22,000 uF: http://www.digikey.ca/product-detail/en/ECO-S1EA223DA/P6591-ND/131411
If you care less about the buzz noise (because you already can't hear it when your hood is closed) and just want to make sure your relay is operating within spec: 500uF at a minimum will work. Regardless, 500 uF will still reduce the noise significantly from what you have now and it may not even be audible. How this translates into audible sound is hard to guess without testing.
680 uF: http://www.digikey.ca/product-detail/en/MAL214651681E3/4502PHBK-ND/2410367
If the buzzing doesn't bother you much now, and you only somewhat hear it when the hood is closed, I'd just go with the 680 uF. It is the small and will get the job done. Otherwise since they aren't to expensive, you can get the 22,000 uF as well and just see how much of a diference it makes.
(the negaticve arrows on the case of the capacitors point towards the negative leg)
Diode:
This will be plenty: http://www.digikey.ca/product-detail/en/1N4002/1N4002FSCT-ND/1532743
-------------------
From digikey you can checkout as a guest. $8 shipping flat rate.
I just remember my side markers flash when I lock the car, so I can't use those. I'll have to stick with the headlight as the trigger.
I think I will go to Sayal Electronics & see if I can pick those up locally. I don't want to wait.
Any ideas on how to package everything so that it can be waterproof?
I was thinking electrical tape & put a heat gun to it?
Thanks
TrainingWheels
Well-known member
Shame, side markers would of made it super easy.
Local makes sense. Weekend is coming up and digikey is 1 business day for shipping so you'd have to wait till Monday.
--------------------------
If you speak to someone locally they should have something close to those parts....although the resistor will be a tricky item to find. You can get a smaller wattage resistor as long as it isn't a film resistor (the film can evaporate after repetitive surges (every time you turn on the system)) so go carbon or wire wound style rated for 52W peak for 300 uSeconds. A great alternative to a low resistance resistor would just be an adequately long spool of high gauge wire (look up AWG copper wire resistance per foot/meter and see what length you'll need for different gauges... 16-28 gauge are typically readily available at these stores). The ripple current of the capacitor is only ~200mA so most wires shouldn't have trouble over heating.
Reason for low resistor value:
A 50ohm resistor will give you a relay voltage of 7.6V
A 25ohm resistor will give you a relay voltage of 9.3V
A 10ohm resistor will give you a relay voltage of 11.4V (acceptable)
A 2.7ohm resistor will give you a relay voltage of 12.1V
.....this is because the higher the resistance the 'harder' it is for the capacitor to fully charge
Any lower than 2.7ohm and your starting current will exceed 4.5A
The diode only has a momentary surge current of 4.5A then settles down to <300mA so the majority of diodes will work.
----------------------------------
To make everything waterproof you can by some appropriately sized shrink wrap. Electrical tape will eventually fall apart due to the changing temperature and humidity under your hood...I wouldn't expect more than 2 months. I'd suggest the shrink wrap method (although large sizes are hard to come by) or layer everything in liquid tape. A plastic box from anything useless would be great too. Cheapest alternative would be to just bag everything and either shrink wrap or tape+zip tie the ends down.
Local makes sense. Weekend is coming up and digikey is 1 business day for shipping so you'd have to wait till Monday.
--------------------------
If you speak to someone locally they should have something close to those parts....although the resistor will be a tricky item to find. You can get a smaller wattage resistor as long as it isn't a film resistor (the film can evaporate after repetitive surges (every time you turn on the system)) so go carbon or wire wound style rated for 52W peak for 300 uSeconds. A great alternative to a low resistance resistor would just be an adequately long spool of high gauge wire (look up AWG copper wire resistance per foot/meter and see what length you'll need for different gauges... 16-28 gauge are typically readily available at these stores). The ripple current of the capacitor is only ~200mA so most wires shouldn't have trouble over heating.
Reason for low resistor value:
A 50ohm resistor will give you a relay voltage of 7.6V
A 25ohm resistor will give you a relay voltage of 9.3V
A 10ohm resistor will give you a relay voltage of 11.4V (acceptable)
A 2.7ohm resistor will give you a relay voltage of 12.1V
.....this is because the higher the resistance the 'harder' it is for the capacitor to fully charge
Any lower than 2.7ohm and your starting current will exceed 4.5A
The diode only has a momentary surge current of 4.5A then settles down to <300mA so the majority of diodes will work.
----------------------------------
To make everything waterproof you can by some appropriately sized shrink wrap. Electrical tape will eventually fall apart due to the changing temperature and humidity under your hood...I wouldn't expect more than 2 months. I'd suggest the shrink wrap method (although large sizes are hard to come by) or layer everything in liquid tape. A plastic box from anything useless would be great too. Cheapest alternative would be to just bag everything and either shrink wrap or tape+zip tie the ends down.
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Sooo...
After I soldered & connected everything it friggin works!! Thank you. Drinks on me if you ever see me.
I can't hear anything at all & actually notice the humming of the hids. I got a .25w resistor by accident. I was concerned it won't work, but it did. Tomorrow I will shape everything up & stuff the box with silicone. This is the largest electrical project I've ever done. I always hated electricals but now its a pleasing challenge.
Cheers
After I soldered & connected everything it friggin works!! Thank you. Drinks on me if you ever see me.
I can't hear anything at all & actually notice the humming of the hids. I got a .25w resistor by accident. I was concerned it won't work, but it did. Tomorrow I will shape everything up & stuff the box with silicone. This is the largest electrical project I've ever done. I always hated electricals but now its a pleasing challenge.
Cheers
TrainingWheels
Well-known member
AWESOME. That's great to hear and overall a clean look.
And you're right, electrical takes a while to get comfortable with but it's easier to learn when you're motivated to do your own work.
I wouldn't worry much about the 0.25W resistor, if it holds up after a month of use then you're golden.... the only reason I gave you the link to a 3W one was because it had stress testing documentation that made me happy.
P.S. capacitors are usually the things that fail first (the top will burst open; so if your relay turns off (the cap shorted) or starts buzzing again (the cap internally disconnected) you know what to expect, most likely from vibrations or overheating) but a standard capacitor is rated for 2000 hours minimum (almost 3 months of constant use) which is already plenty.
P.S.S. If you're super unlucky and the cap shorts when it dies then it'll take out the resistor, then if the resistor shorts when it dies, it'll take out the diode, then if that shorts it'll take out your PWM unit LOL but that's a cascade of unlikely failures before reaching the PWM unit.
+1 for velcro tape
And you're right, electrical takes a while to get comfortable with but it's easier to learn when you're motivated to do your own work.
I wouldn't worry much about the 0.25W resistor, if it holds up after a month of use then you're golden.... the only reason I gave you the link to a 3W one was because it had stress testing documentation that made me happy.
P.S. capacitors are usually the things that fail first (the top will burst open; so if your relay turns off (the cap shorted) or starts buzzing again (the cap internally disconnected) you know what to expect, most likely from vibrations or overheating) but a standard capacitor is rated for 2000 hours minimum (almost 3 months of constant use) which is already plenty.
P.S.S. If you're super unlucky and the cap shorts when it dies then it'll take out the resistor, then if the resistor shorts when it dies, it'll take out the diode, then if that shorts it'll take out your PWM unit LOL but that's a cascade of unlikely failures before reaching the PWM unit.
+1 for velcro tape
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Thanks for reminding me, I have velcro tape lying somewhere in the garage.
Also that pic is taken in the testing phase
Everything has been tucked away and the electrical tape has be replaced by insulated prongs & plugs.
I think if anything shorts, hopefully the fuse for the headlamps will pop first.
Its funny, because I couldn't figure out what the wattage for the resistor was for. Is it the power consumption of the resistor itself or the "max amount of power" that the relay coils can be? I was up all night thinking about that, lol. I end up getting another resistor at 2W but did not install it. It was too much work to re-solder everything. I ran the .25w for a bit & it doesn't overheat, so that's good.
Its funny when I shut off the switch the headlights remain light for 0.5-1.0 secs. I think the cap retains a bit of charge or it was overkill
