I am trying to mod my electric dual cooling fans to come on with a flip of a switch. I have read a bit about it on the net, but have had no success with the methods I've found.

I read that if I splice the wire that goes to the Coolant Temperature Sensor on the passenger side of the block, and add a switch that is grounded, the fans would kick on when the switch was on, I tried grounding the wire to the Coolant Temperature Sensor, no fans.

I also read that if I ground the green/white wire at the Fan Relay, the fans should turn on, although I didn't know where to look for the Fan Relay, since my book doesn't show specifics for my year (1987). If anyone knows, please inform me.

I was just wondering if anyone had done something like this sucessfully, and if they could assist me a little. I am somewhat confused, and beginning to wonder if I have a problem with my cooling fans somewhere along the line. I know 1 fan kicks on at what my temp gauge says is 225-230, although I do not know if the 2nd fan kicks on, as I never have seen it on.

I really just want to be able to kick my fans on in traffic to cool down my engine, I have no troubles with heat while on the freeway, or going over say 35 mph. I am pretty sure the Thermostat has already been swapped out, since It does run around 175-180 on the freeway, although I have not checked what thermostat it has in it. I have read about kits and replacement sensors, although I just want to do it as cheaply as possible, and be able to control it very easily.

Thanks in advance guys!

 

Grounding the wire you mentioned for the secondary fan (pass side) temp switch should have made the pass side fan come on if key was in the run position.
Not sure where your fan relays are located since my car didn't originally come with elec fans, but would think they're near the fans somewhere. Looking at my transplanted GTA wiring harness, it looks like the fan relays are at the front pass side corner of eng bay.

Need to locate these relays and check for voltages. You may have a bad relay preventing the fan from getting power.

On my car, I burned a prom that will turn on the primary fan when coolant temp hits 205 and turns it off at 190.

I also have a switch that provides a ground for the secondary fan relay so I can run it when stuck in traffic.

I originally had both fan relays hooked to the same switch. When you turn-on both fans at the same time, it really strains the elec system. On my car, I measured 70 amps for both fans at start-up!
This created concern regarding the alternators expected lifetime.

Also, if you run the A/C while parked, be sure at least one of the fans is going. Otherwise the A/C system will create excessive pressure and may relieve itself,, one way or another.

 

I found the relays and checked that each fan runs, by jumping from the orange wire to the black/red wire. As for a bad relay, I don't know.

Willie is currently helping me through e-mail on this project, and I expect everything to go smoothly now.

If anyone else is looking for the relays, they are located in the front passenger side of the engine compartment, next to the air cleaner (on my car) and in front of the evap canister.