Got an 85' Trans Am project that I'm going to be putting the radiator fan into soon. Can anyone tell me which relay on the firewall is for the fan (part number)? Since I don't actually have the fan in there, I can't actuate it and check. Also, I was told a dark green wire goes to the thermo switch, which threads into the block on the driver's side, but that's where I put in the temp sender, and that dark green wire appears to be for my temp gauge, as it works correctly and goes all the way to "hot" when I ground it out. There is another green wire right next to it, along with a tan wire as well. Are these for the fan? Thanks!

 

You really don't want to use the 85 fan relay. I mean it works under ideal circumstances, but if you're customizing anyway... You might as well pick a modern Delco/Delphi/whatever, waterproof relay, matching pigtail, and more reasonable temp on/off fan switch, and wire it up. That way you get a NEW relay that has a chance of keeping up with the current draw, fresh clean wiring that you can choose to support the load, and you'll have the chance to make it all weather-proof.

On the other hand, you can stick with the early relay and hope it doesn't melt.


Green wire to sender in the driver's head is the temp gauge sender. Tan wire on the drivers side is probably for the warning switch in the brake combo valve.

 

What is the warning switch's purpose? And thanks for the tip, I'll just wire something up myself. Any idea what the other green wire might be? I've also got a black wire by the carb that is NOT a ground wire, some day I'll figure out what all this is, I'm sure.

 

The switch tells you if there's an imbalance in the front/rear circuits of the brake system by turning on the dash brake warning light... For instance, when you're hurtling down an off ramp at 100mph+ and you hit the brakes, then feel the pedal drop to the floor as all brake feel goes away and the car stops slowing down, the brake light will come on to let you know a front hose just let go. Very useful.

The other green could be the horn wire. Black near the carb is probably the choke wire.

 

Got it. Thank you!