I've searched the archives, but didn't really find the info I'm looking for. I have a 90 Camaro with TBI and auto. Right now, the fan isn't coming on, so assuming the fan itself isn't broken, I would like to wire a manual switch to turn it on. The reason I want to do this is because I have to pass emissions. I went last weekend to the testing station and the car overheated (even though they put a fan in front of the vehicle, it obviously doesn't simulate actual driving well enough because the car has never overheated in normal driving conditions even after the fan stopped working). Anyways, I'm looking for detailed instuctions for installing a manual fan switch specific for my car with the single fan setup. It doesn't have to look pretty, just be functional. The reason I'm not fixing it the right way is because an LT1 is on it's way in May or June so I'm not gonna put more than a $2 switch into this engine. Oh and btw, the stupid emissions people failed me because I couldn't take the test without overheating.

Any and all help is always appreciated. Please get back to me soon, as I am a college student and I can only work on my car on weekends.

Sorry this is so long, but I had to vent a little about the emissions people that sat there and continued to test my car as the temp gauge climbed past 260.

 

If your car is getting that hot, you might want to check for other things like a stuck t-stat, bad waterpump, hoses, leaky radiator cap, or bad coolant. Any to do this, disconnect the a/c high pressure fan switch (this is located on one of the a/c lines leading to or from the condenser...can't remember). I believe the two wires are green and gray. Before you starting cutting, make sure it is the right one. You can do this by turning the car ignition on (you don't have to start it) and jump the two terminals in the connector with a piece of wire. This should ground the relay and turn the fan on. Cut the connector off, and connect the two wires to a switch. Run extra wire and so forth depending on where you are mounting the switch.

 

Erik,

There should be a fan control switch in the right cylinder head, with a single dark green wire attached to it. This is the same wire that is on terminal 'B' of the fan relay. Grounding this wire while the engine is running should cause the fan to run. If not, the fan relay or fusible link is suspect.

If the fan does run when the wire is grounded, the temperature switch has probably failed, and should be replaced (about $9.00).

 

I've seen the same thing happen to many cars before. My old 92 V6 did this all the time. You let the car idle in traffic or drive under 30 or so for a long period of time and it overheats cause the fan isn't coming on. If you want a really easy solution crawl under the front of the car and look at the plug coming out of the back of the fan motor, it should have two wires in it. One is positive and one is negative. Just use a tester and find out which one is the positive and run a wire from it to your switch. Then you just ground your switch and find a power source, I just ran a wire straight from the battery, and your done. When u turn on the switch it should send power directly to the fan and bypass all the sensors and whatnot. This works well to, because if your cars fan system is working it will still be able to turn on the fan. If not you have the switch.