84 Z28 L69. Cooling fan wasn't turning on and car overheated. I've searched and searched and am curious if I found the issue. Brand new radiator, thermostat, hoses, and fan motor. Ran the car up to about 240 (dash gauge) and fan didn't come on. I located the cooling fan switch between cylinder #6 and #8 tonight and as per other posts, I grounded it to the battery and could hear the relay clicking away. I busted out my service manual and it said to take a wire and ground the dark green wire in the fan relay (I assume with the relay taken off and a wire from pigtail to ground) Upon running a wire from the pigtail connector to a ground I got nothing.

If I read previous posts correctly, the relay clicking means its bad? Although I don't understand how the fan would have power with the relay off if the power wire runs through the relay. Also when I pulled the relay off, there was a dark brown greasy substance on all the contacts. Is this normal or did something go wrong? I'm ordering a new relay tomorrow but would really like to stop throwing money at this. Thanks.

 

Also, after putting the fan back in its mounting spot, it has resistance when being turned by hand...as if its hitting something, but everything is mounted in its original spot.

 

Fan blades should not be hitting anything, there will be some resistance but it should spin freely without making any scraping sounds.

The brown goo is old grease that has dried out. Try cleaning it up first, that might be your problem.

Don't buy a relay just yet. When you test the green wire by applying ground to it, it must be plugged in. But you can skip that test because you already know that connection is good when you did you grounding the switch wire test and the relay clicked. Usually if the relay clicks, it's good, but not always. The next thing I would check is if the red wire at the relay has power, it should be 12v whether the key is on or not. If yes, ground the wire at the switch like you did earlier to make the relay "click", and make sure you are getting 12v at the black/pink wire on the relay. If no, buy a new relay.

 

Ok so I checked what you said. I get 12v at the red wire with key off and on. I then grounded the switch at the battery and checked the black/pink wire (mine is brown/white see attached pic) and I got 12v. However, when I ungrounded the switch, I checked the black/pink wire again, I was still getting 12v with the relay plugged in and not plugged in. So it would seem my black/pink wire is always hot.

I then disconnected the pigtail at the fan motor with the engine block switch grounded, relay plugged in and got a big fat ZERO when I tested the pigtail. I got no reading at all, so it would appear that power does flow through the relay but is getting stopped somewhere before it hits the fan motor itself. I've traced back one wire back to the pigtail and it looks intact and good. I still have to find out where the other wire goes. It looks like it goes towards the front of the car somewhere.

 

Make sure you are testing the correct relay.
I'm not sure on the older camaro non tpi cars but the TPI cars have the fan relays up by the rad core support. A factory service manual will help you a bunch.

 

Ok so I'm an idiot or inadvertently fixed the problem. I cleaned a ground that is up by the drivers side headlight that goes into the same clump of wiring as the pigtail harness. I checked it then and got 12v......also the fan was in too tight and couldnt rotate properly. Took the fan out from it's mounting spot and it runs fine now.