1989 IROC-Z 350 TPI

I've had the car for a little over 2 months now, and since the day I bought it, it's had overheating problems. We're talkin constantly staying from 220-240, and in some cases, it's stayed at 260 for a few minutes. It's gotten bad.

The primary fan won't come on until the secondary fan comes on at above 220. The wires look ghetto-rigged.

Tonight, I gas up drive around town and all, I decide to park someplace. Both my fans stay on after I had turned the car off. I leave thinking they'll shutoff soon. I come back 30 minutes later, and they're still on. I tried seeing if any wires were crossed or whatever, turned the A/C off and on - anything to get those damn things to shut off. Nothing. The only plus is that I was running cool the whole time I was out - never getting above 150-180.

I just got sick of it, and disconnected the battery so the fans wouldn't run all night. Any suggestions or ideas on how to fix those fans??

 

First, the primary should run at 220 or so. Aux at 243 unless it's been changed. The only way the fan can run if the key is off is if he wired the coil side of the relays to ever present 12 volts. You will need a wiring diagram, a voltmeter and a fundamental knowledge of how to troubleshoot electrical circuits. The relays have 2 internal sides. One is the contacts, they can be identified by the heavier guage wires from the relay socket. One of the heavy wires has 12 volts all the time even with the key off. The other side of the relay is the control coil identified by the 2 lighter guage wires. One of the coil wires will have 12 volts only when the key is in the "on" position. That is to prevent the fans from running after the key is off. Someone changed it as usual, to most likely correct an intermittent cooling problem. If you can, restore all the wiring to stock, hopefully if anything has been cut and spliced you can reconnect to the old wiring going by the color codes for the wires. Use heatshrink to seal the splices to prevent corrosion. Then replace BOTH fan relays. Fire it up and try it, primary should run with A/C on or when you hit a little above the center line on the temp guage. If the fans run when needed there is no reason to modify them assuming the cooling system is up to snuff. Pm me if you need help.

 

Got the problem fixed, now the fans operate when I turn the key to the run position. It's fine that the car runs nice and cool, but I just don't want those fans on all the time. I'll do what you said and replace both relays and fix up the wiring, and I'll go from there.

Thanks for the help!