Why my fan stay on?!?!

[Crazy D]

My coolant fan has stayed on indefinitely after turning the car off a couple times in the last 5 or 6 drives. WTH could this be?


...and why won't anyone answer my tach question? I put in a thread, then it's own thread, and nothing. *sniff* Nobody cares.

 

[mar86gn]

Well it sounds like your fan delay relay is going bad. It's the big one of the three on d/s. Does it never shut off? It's supposed unless you have an overheating problem.

 

[Crazy D]

It just did it again, yeah. If you unhook the battery the on again, the fan kicks right back on. Is the fan delay relay something any auto parts store will have or do I have to go get screwed at a dealer?

 

[pwrhws]

I have also had a High Pressure a/c switch (by the alternator) go bad and the same thing happended.

 

[MARINES185]

i also had this problem and its more than likely the cooling fan
temperature sensor. this is the one wire sensor just above
the 2 wire engine coolant temp sensor. both are on the right
hand side of the throttle body. to test is turn car to run position
and get fan going. then unplug the one wire sensor the fan
should stop if thats the problem.

 

[Mr URL]

Try tapping the fan delay relay with a screw driver handle on the driver side fender. Might make it shut off until you get a new one.

 

[GNVenom]

There is only one thing that will cause the coolant fan to run indefinitely after the car is shut off...that's the Delay Relay. No other switch has an un-switched connection to the fan control. I've been preaching this for years...just remove the delay relay altogether. It really doesn't serve any genuine purpose unless your car is entirely stock. It worked well when we used the 190 deg t-stat, but we've pretty much all converted our cars since then. Better radiators, 160 deg thermostats, front mounts, all that stuff. The fact that half of that delay relay is wired to live 12volts and the other half is wired to switched 12 volts...PLUS, there is a ground wire to the unit. Breeding ground for a nasty electrical snafu. Just get rid of it!
-John Spina
http://www.casperselectronics.com

 

[John Larkin]

Just get rid of it!

What he said. It cost WalMart 2 batterys before I figured it out.

 

[Hawaiian Turbo]

Would that be the one closest to the firewall?

 

[Bryan 94 Z28]

I was able to stop the coolant fan by tapping on the sensor/switch that is mounted on the A/C line just next to the alternator.

I guess we need to buy a new one of them. Anyone know where to get one, and how much it might be? Anyone have the GM part number by chance?

 

[GNVenom]

The fan delay relay is the largest relay of the three, found on the drivers side inner fender well. There are two plugs on the unit. Remove BOTH plugs to disable the relay. This relay is unsealed, causing a potential for failure (every GN has had the same problem, but rainy conditions cause it to fail sooner). There are only two things you can do; replace it or eliminate it. I'd go for the latter...
-John Spina
http://www.casperselectronics.com