The oem heater lead has two wires. Ground and hot.I checked them with a multimeter.Are there other pins on the relay? Are you sure you're on the right one?
Do you have a 110 to 12v power supply that you can use to provide power, and check if it's that connection?
 
	 
  
  
  
  
  
  
  
  
 
		 
 
		 
	 
  
  
  
  
 