AC/Cooling Fan Killed Battery - Engine was Already Off
 

Strange situation with the AC in my 1986 coupe. It did not work for 2 years, tried recharging and no luck so I assumed compressor was bad. Well lo and behold the AC started working again now that it’s hot outside. Still not sure how that happened.

Anyway the other morning I drove the car to work and used the AC. Turned off the engine and the cooling fans were still running, even after car was shut off. Google implied this is normal on Vettes so I paid no mind.

Left work and had zero battery. Had to jump-start it. As soon as I connected the last jumper cable the radiator fans turned on - again, no battery power, no key in the ignition. The AC controls inside the car were set to “off.” Took 15 minute recharge and car started.


I don’t know how to troubleshoot what’s wrong but I’m guessing at this point that my compressor is OK and I have a switch or relay problem of some kind. Any help?

I would suspect cooling fan relay is sticking.

Sounds very plausible to me, based on the description.

Do you have the manual AC control or the C68 electronic controller?

I have manual AC control. Also before I could only select Lo and Hi fan speed. Now I can choose between all 4 and it blows air at all speeds. Max is still pretty weak.

If it’s the relay, is that easy to find and replace on my own? Only other one I’m familiar with is the fuel pump relay because I’ve considered replacing that one.

:iagree:

I've experienced this before...only difference is I happened to catch it before it drained the battery. New relay was the ticket! One of the easiest fixes you'll ever have. :thumbs: