The fans in my car are acting very weird. First off the driver's side fan doesn't come on anymore. The pass side works when the air is on (which I believe is normal), but it sometimes can take 15-30 seconds for it to do so. Not really sure if that is normal. Here is where it gets odd. Today I was driving it trying to get it to heat up, and got back to the house and let it set for a few minutes, running. I was switching the air on and off to check the pass side fan, and when the temp got to around 240, the pass side fan kicked off, and the driver side fan came on. Any idea why it's doing that? It's only happened once. I haven't tried to recreate that situation yet. I already considered the relay, but I'm not really sure how to check it. I read on here before how to do it, something about grounding it out or something. If someone could help me out I'd be greatful. The only thing I know that has been changed on the car is the last time(about 2 yrs ago) I had it worked on for overheating issues the mechanic said he put a sensor on there that would make the fans come on earlier or something. Not really sure if he meant the tstat or what. Anyway, I'm not really having overheating problems, the fans just aren't working properly.

Thanks for the help.

No one has any advice?

On dual fan TPI cars, the driver side fan will come on when the AC is on and the car reaches a certain (HOT) temp 236 - 242. Remember that the temp gauge in the dash isn't the most accurate. Since the fan did come on then you can rule out it being the fan motor. I'd check the coolant temp senor, which is in the front of the car, not the temp sending unit that is on the driver side which sends info to the gauge.

Not entirely convinced that the fans are not working properly. Normally, the fan(s) wont start to run until either the a/c is put into service or the operating temp reaches 220+ deg then the fan switch goes to ground and starts the fan.

If the car is not overheating (240's too hot for me to be happy) then, you may have no problems at all. GM designed these cars to run hot.

@VA1991Z28

Well, it's the driver's side fan that doesn't switch on, at all, except for the instance that I mentioned above. The pass's side comes on after I turn the A/C on. I had considered the guage not being very accurate, but it wasn't erratic or anything so I thought it was probably close enough. Btw, where exactly is the coolant temp sensor, and what exactly does it look like. I'm not very familiar.

@Wadebryant

The problem is not really overheating, the problem is that when the car does get hot (like you said I think 240 is too hot, too). There's nothing there to help bring it back down. I had also considered that these cars are designed to run hot, but I still feel something is not quite right.

Not text book or how someone else might trouble shoot the problem but, here's a couple of suggestions.. you'll have to diagnose it as you go.

Determine if the non working fan circuit and finally, if the motor has a problem. There are a couple of methods that you can use to test the fan operation.

First, locate the fan switch wire. If your car has the stock exhaust manifolds it'll be hard to see from above but, it's located between the #6 and #8 cylinders down near the spark plugs on the head. It has a single wire to it with a male pinch style connector. By the way, these connectors are often brittle from heat. A bad connector can be a source of fan trouble.
If you cant see it or find it from above, jack the car up, crawl under, and look from underneath. Disconnect it and go back topside. Pull the connector up and inspect it for damage. Insert a piece of wire into the connector and ground it. (you can also use a crimp on splice / connector and temporarily splice your test wire to the fan switch wire for your ground test)

As mentioned in a previous post, you can ground the fan switch wire and start the car (the fan may also come on with the key turned to the acc setting). If the fan activates, the fan switch is probably faulty. If the fan does not come on, use an ohm test meter to ensure that you have continutiy on the wire circuit to the fan and ground. If the fan switch wire circuit is good, and the fan does not activate, check the fan relay next.

The fan relay is located above / behind the brake booster on the firewall. You will have to determine which relay controls the non-functioning fan. If your car has two similar relays, start the car and turn the a/c on. Disconnect the relay's one at a time until you find the relay that controls the running fan. It shoud be the other relay that you're interested in. If you have an ohm test set, check across the poles and see if it has continuity. If not, or you dont have a test set, you can either purchase a new relay (not too expensive) or invest in a test set b/4 you start this project (a must have item for electrical trouble shooting etc.). I would also suggest that you test both relays with a test set to compare b/4 you purchase a new relay... If the relays are okay, and the fan still hasnt run, suspect and check the fan motor.

If you get to the point where you think that you might need to remove / replace the fan motor, first disconnect the battery and wires to the fan. Make up two insulated wire leads. Connect the test leads to the battery. If the fan doesnt run now, the fan motor is bad.

Sorry the post is so long but, hopefully you might get an idea from these suggestions.

W

Thanks. That was the sort of thing I had in mind, but I just needed some direction as to how to go about the troubleshooting. I'll give it a shot next time I get a chance to work on it.

Does anyone know where the fan relay is on a 92 RS w/ 3.1 v6. Fan does not come on and have replaced the coolant sensor in the manifold still no fan. Fan does run when we disconnect the coolant sensor,parts stores here do not know hwere my fan relay is .thanks alot