I have an 86 IROC with a 305 the fan does not work,I replaced the fan motor and still nothing.I was thinking it might be the temperature sending unit since the temp gauge doesnt work.The fan terminal reads 12 volts with the ignition on.Does anyone have any ideas??Any help would be greatly appreciated.Also does anyone know where the temperature sending unit is located on an 86 IROC with a 305 TPI? THANKS

[ 05-27-2003, 09:18 AM: Message edited by: Noalternative86 ]

Mine is one the water pump. Looks like a spark plug sticking out. Made out of brass. It's gotta be close to the pump. Look for a wire going to that area to covered connector plug. It came out with a 3/4 in socket.

Later,

JohnsonB

well since no one else has touched this I will attempt to offer some ideas. Your electric fan is controlled by a temp sensor that is connected to a relay. When your temp gets high enough it grounds "turning on" the relay and energizing the fan. There should be a fuse to the relay. First off you should check all of your fuses with a test light to ground and the key on. Another "quick test" would be to run the car with the A/C on -the fan should come on and stay on. I also think that if you jumper the ALDL connector and put the computer in the diagnostic mode it should run the fan as well. If the fuse tests good you need to locate the sensor and you can unplug it and use a test light to ground it -this should make the fan come on -if not you need to locate the relay. There should be four wires (maybe more) 2 small and two larger wires. Use a test light to ground to see if there is power to either of the two larger wires (ONLY the larger wires -- in some cases the relay is controlled by the ECM and sending 12v to the wrong one may have adverse affects on your ECM!!) -If the wiring checks out try jumping a wire across the larger wires --fan should come on. if it doesn't it is probably your fan -if it does it is probably the relay. -****If you really don't know what you are doing it is advisable to take it to someone who does. Poking around with a test when you don't know what you are poking can be expensive! **** -I am just trying to offer some suggestions!! Perhaps some others will jump in here with some other ideas. My guess is the relay-common problem.

Hey, i have an 86 iroc as well, and i just purchased the sevice manual for it. but just our luck, it is in my car at the body shop. my car must have had the same problem, because my fans are always on when the key is on. i have never had any problems with that set up. i would suggest it, unless somebody else knows something about damage it may cause? if you need anything from the service manual... shane_c2003@hotmail.com