Hey new to the site just need some help figuring out a coolant fan issue I'm having. I have a 92 RS 305 5 speed. Coolant fan comes on with AC but not when I switch it to defrost. Now I thought that it was supposed to come on in defrost but I've viewed a few wiring diagrams with the coolant fan circuit highlighted and none show the defrost involved with the circuit besides being part of the HVAC controller. They are cheep like 3rd hand photo copies from aldata. Question is, is the fan actually supposed to cOme on with the defrost ir not? I've read and heard both sides of the coin and still have nothing definitive.

 

i would say no. my 92 pickup was the same way. the kid should be around to confirm later.

 

did you check to see if the a/c compressor is turning on? if not, might just be a worn out hvac switch. cant confirm it because my a/c is currently disabled

 

the compressor does work with defrost but the cooling fan does not run. It only runs when the A/C is engaged. Yes Regis, that's my final answer


ps- I was just messing with the hvvac controls a few hours ago to make sure the diverter underneath was functioning before i buttoned up under the dash. I found it curious that the cooling fan isn't on with defroster