Is there a place I can tap into the ecm harness on my 89 IROC to install a manual fan switch?
On my 95 all I had to do was tap into a lead, can't remember which, at my ECM. I ran a wire from the tap, to a switch, to a ground. With the switch off, my fans come on normally at the preset temp. Which is around 175* since I reprogrammed it. With the switch on it will turn on the fans until I switch it off or turn off the car.

I think there was a problem with my fans anyway. I haven't run it or driven it very far, but I've seen it get to 220* but I never heard or saw the fans come on. Also it doesn't come on when I turn on the A/C. It does on my 95, is it normal for it not to on the 89? Another question is, There are two wires cut at my fans, one red and one black, they are close together, but I don't see what they were cut from unless the other side slipped back into the split loom. What color are the wires that go to the fans? Thanks A lot.

 

I unplugged the harness from my factory fans and installed dual Flex-lite fans and then ran to a switch off my console. Should be pretty easy to do, just need a positive/negative lead and a switch from like O'Reilly's and your set.

 

I really wanted it to stay stock with the option of manually starting the fans. If I'm in town and I don't remember to start the fans, I want them to start by themselves like they should, you know? At least until I can get a Prom that changes the "on temp."

 

Simple, rig the fan motor to a 12v source with a fuse in between (I used the battery terminal), and run a 4$ switch anywhere near the drivers seat.

 

Look for the green wire on the fan relays. Splice into it but don't cut completely. Run a wire from the green wires to a switch inside your car, then a wire from the switch the a ground sorce such a the body. when the switch off the fans runs with the stock setup. but with the switch on the fans will run all the time. The good thing with this was, nomatter if you leave the switch on, when you cut the car off the fans still cut off with the car. So no accidental dead batteries.

 

That's what I was looking for. Thanks a lot. Like I said above, on my 95 Z28 it splices in along the ecm wires.