I finally got my Firebird on its own wheels again and drove it around a bit. Today I went for about a 45 mnute drive and the fan kicked in at the right times etc. It was basically stuck right at 220 F or a bit under after it warmed up (good thing I guess). The fan only really kicked in when I was waiting at a red light. I got home and parked it in the garage. About five mins later I went to get the stuff I bought out of the back and the coolant was boiling. I turned the key to the run position (didn't start it) and the coolant was right below 260 F... Not good.. I left it in "run" mode and popped the hood to let it cool off.

Shouldn't the fan run when the engine is off? It doesn't overheat when running, only after driving a little while and then shutting it off. The sticker on the fan shroud mentions that the fan can come on at any time, but mine clearly does not.

So heres a run down: Car at soemthing over 220F, the fan is running. Shut car off, temp rises, fan shuts off with ignition

If it isn't supposed to run with the engine off, canI rig it to do so automatically? I don' want to mess with switches and kits. I just want it to cool things the way GM intended at least for now.

It's a 305 V8 TBI if that matters. I only have one fan.

 

turn the a/c to on(max ,norm, or bi)(yes, eng. off) and the fan should come on(if wired correct and no other problems

 

So the AC needs to be on for the fan to be on and the engine off?

I'll try it next time I get it warmed up

 

Didn't work man, I guess I'm gonna have to try some wiring

Is the fan supposed to run with the engine off though? Because if its not, I have a lot more work cut out for me.

 

yes, it should come on with the engine off, the wire to the fan switch(or ecm) needs to be grounded(through the fan switch or ecm) or the A/C switch needs to do the same, ground that wire

make sure the relay is good, the relay for the fan is the same as the heater blower relay, so switch them and see if the fan works with the A/C on(quickist way to check relay)

 

The fan as wired from the factory will NOT run with the key off/engine off. The underhood sticker is misleading to some degree, but it simply means the fan can come on anytime with the appropriate rise in engine temp. You don't want the fans running when it's off, it will drain the battery depending on circumstances. If the coolant is boiling you may have a pressure problem. A typical TG on a hot day after it's shut off depending on the engine temp when it's turned off will rise 20-30 degrees then start to cool. That's because there is no water circulation. Some imports run the fan off a timed control circuit in the ECM after the car is off, mainly because of the aluminum engine components. If you ever noticed that in a parking lot you will see when they run it's in very short bursts. Your car is working the way it is supposed to, you may want to do a cooling system check, e.g., rad cap, coolant condition and mix etc.

 

Ok, the coolant is pretty nasty. It's more borwn and chunky than clear green. I guess I shoudl fix that LOL. It'll have to wait until I get a new clutch. Pushing a Firebird down a state route isn't fun. When I flush the radiator, I'll get a new cap too.

Turning the AC on turns the fan on when the engine is running - good tip, I'll remember that incase I want it to cool down a bit before I shut it off.

Thanks for the help!