phishfud

iTrader: (1)

I just started having this intermittant issue with my 88 GTA. Car doesnt run hot, and always ha dthe fans come on whne they should, until last week. I noticed that my car was running really really cool all of a sudden. I thought maybe the gauge was goofy, but I noticed that as soon as I turn the key to ON, bot fans are running, and stay running the whole time I am driving. I have also noticed that this doesnt happen all the time. Will sometimes heat up to normal, and while driving, both fans come on and stay on. I do smell some coolant, so I know I have a small leak somewhere (just cant find it, but leaves no puddles, and system is full, go figure). Anyone have a clue as to what it up with my fans? Thanks in advance.

Terry

Danno

Two things can cause this. Whenever the aux fan is requested the primary fan comes on. On the pass side around cyl's 6&8 there is what they call the aux fan switch. It closes to ground when the temp hit's around 238 degrees. When it closes it turns on the aux fan relay, but it also sends a default signal to the ECM and turns on the primary fan even if the CTS is not reading high enough for the ECM to normally turn on the pri fan. That sw could be bad or the wire may be shorted. Second, if the vehicle has A/C there is a pressure sw in the A/C system that is normally closed until a certain pressure is hit. This is a common problem when guy's do the A/C delete, they leave that plug open and the fans run all the time. You could have a problem there. The aux fan sw has a single wire, you can simply pull it off to see if the pri fan turns off when it's cold. I would get a pressure tester and see where the leak is, you could be losing cooling system pressure and developing hot spots in the block causing the aux fan sw to turn on.

phishfud

iTrader: (1)

Thanks for the help. That makes total sense, since the connector for the aux fan switch doesnt click on. I did a header swap recently, and the switch connector just pushed on, but didnt seem to want to stay in place. I'll have to investigate that further and see if a new end is available somewhere so I can fix it. Thanks again.

Terry