Hey everybody, just wanted to start out by saying hello!

I just got an 86 Camaro. It's a base model, with the 2.8 Liter. Everything appears stock on it. I got it dirt cheap, it runs great. One of the quirks I'm having is that the fan NEVER turns off. I can't find anything that might hint at someone directly wiring the fan to the battery or anything other than what it should be. I actually bought it off of my friend, and he's replaced several of the sensors. I'll do my best to get the names of the sensors that we replaced, so it will help to narrow them down - the cold start switch is sitting in front of me, waiting to be replaced. Believe me, it took us most of this past evening at advanced auto, looking through their catalogs to get a hint as to what it was. I took a stab in the dark and looked up a few numbers on it over google, and found out what it was. When I shut the car off, I have to disconnect one of the wires to a sensor or module, just so it doesn't kill my battery. Someone suggested that I run a wire into the fuse box (like to my radio fuse slot - something the ignition kills when off), then the other to the fan, though I want it done properly.

I'm replacing this cold start switch as soon as I find someone with one, and I'm going to replace the sensor that acts as a thermostat, because the temperature gauge doesn't work properly. I know it may not need to be replaced, but seeing as this engine is 17 years old, I don't mind putting the parts into it. The car drives great, though it's not a V8 like many of you all have. It's my first (and closest to being) sports car - I'd like to give it all of the TLC that I can. I don't race it, or rag on it. Any help or ideas offered are greatly appreciated. Also - when it first starts up, it idles like a harley, then revs up from 400-500 up to around 1500 then back down, it's a slow change, other than it just being cold - I know they didn't do this from the factory - could this be an idle control sensor or module of some sort that needs work? Once it's warmed up, it idles better, so maybe not. I'm new to this engine, so any other suggestions are welcome. Sorry for the long read, I just want to supply all info that I can. Thanks again everybody!

MJ

 

Welcome. Nobody knows whats really under the hood unless you tell them. According to my wiring diagram the ECM controls a fan relay on 86 V-6. Pull out the fan relay. If it stops replace the relay. Sometimes the relay contacts weld themselves shut. That is about the only thing that would cause it to run after you shut off the key. The relay should be on the driver side firewall near the fuel pump relay. Need help identifying parts, use www.acdelco.com and punch in the vehicle info as prompted. They identify almost every part and the good part is that you usually get a picture of it. Great way to get a leg up on whats what under the hood. Good luck, and yeah they are pretty. I just finished having my 89 iroc completely reshot in the factory color clear coat. Can't decide what to do about that 2001 SS I am looking at. Keep me posted on how you make out with it.

 

We replaced the fan relay switch, and the coolant temperature sensor. The thermostat has also been replaced. I'm currently looking at the two sensor/switches on the driver's side of the engine - one has a single terminal sticking up, looks familiar from last night, after digging through all of those books. There's another one that's got a larger plug on it, trying to figure out what it is as well. I did look through the haynes manuals while I was there, and they're about worthless. I might have to get a special one ordered from Chilton's, hopefully they're more helpful.

 

Guage sender has a single wire on it, other one might be knock sensor. Does the fan shut off if you pull the relay?

 

Yep, it shuts off. That's how I'm toggling it for right now. I know I can run a toggle switch to it, but I'd rather fix it properly.

 

Ok, next step is this. The relay coil gets its voltage from a key on or "hot in run" voltage source. Even if the ECM has a shorted driver the fan should still turn off with the key. Contact side of the relay is fed directly from the battery through a fuse link and is on all the time. Pull the relay and with the key off you should get 12 volts on only 1 pin of the relay socket most likely the red wire. Of the 4 wires 2 are heavy guage, they run the fan. The brown wire( lighter guage) is the key on source for the relay coil. The grn/wht goes to the ECM and is grounded by the ECM to energize the relay. Thats where guys insert a manual switch. Find out why you have 12 volts with the key off on the brown wire and half the problem is solved. As I said, even in the worst case and the ECM has a bad driver for the relay the fan should still go off with the key. Let me know how you make out. And yes, I like fixing things instead of a hack job. We'll get you through it.

 

Upon further investigation, and after replacing the cold start switch, it turns out that the actual problem is, the fan won't kick in when needed. I checked the wires for any bare spots, frayed ends, connectors loose, jiggling the wires while the fan was on didn't make a difference, either. Seems like the wiring itself is ok, though the only way I can be sure is to check with a voltmeter. I'm hoping to do that as soon as I get my hands on one. Also, there's one switch left to check, I believe it's actually the cooling fan switch, but I can't find one in stock anywhere. I also found a small leak in one of the hoses leading to the heater core. Talk about a fun project. I can't wait to get it the little things fixed up. Thanks for the help so far!