I'm getting tired of my temp rising and falling as I drive. I know my '87's cooling system isn't TOP notch, but its close. New water pump, new hoses, new coolant along with flush, new 180* thermostat.... radiator is all that remains of the old.

Anyhoo - I still can't stand to see my temp rise to over half and wait for the lousy first fan to kick on. The stock settings were WAY too high and I don't feel like putting my engine's care into the hands of a relay that in one way or another, always seems to be out in all of my cars!

Here's my solution:

FIRST FAN: Will be wired in so that when the ignition is on, so is the fan. To disable this feature in the winter or other situations where its not needed, I'll have a switch placed before the splice into the ignition. Easy... Where is the best place to splice into? I would GREATLY prefer a source underneath the hood so that I don't have to run wires into the cabin for this fan.

SECOND FAN: Will be wired into the car with a switch somewhere either in the console or dash. It will be my secondary fan switch that _I_ will control as needed. Question: Is there a power source, either constant or w/ignition, that I can use with the second fan INSIDE THE CABIN? I was thinking either the cigarette lighter or the trunk hatch release. Any pros or cons to using constant or ignition only power?

ANY help would be great. As for connecting the fans this way, I plan to unplug the factory plugs from each fan and tuck them away somewhere hidden. I can get the replacement plugs for my wiring from the local wrecking yard from another GM.

THANKS

 

You should not run the 12 volts for either fan through the ignition sw. It will fry in time. You need to control the fan relays. Use the diagrams in ******* article or elswhere on the site. A single fan can draw as much as 10-12 amps on start up x 2 for both. Thats why they use a relay and a fusible link-the in car wiring is too light.

 

the easiest way would be (if your dual fan setup is using all factory wiring):

if you want the drivers side to come on with the ignition, simply find the wire that goes from the cts to the relay, splice into that with a wire and run that wire to a simply toggle switch and then run the other side to a body ground, you could mount that switch anywhere under the hood.

for the other fan (aux. passengers side) find the wire going from the fan switch to the other relay, spice into that go inside the car, hook up and mount another simple toggle switch and then hook the other wire to a body ground inside or in the engine bay somewhere.

if ur not happy using the stock relays, go get new ones then, but its a good idea to use the factory setup and just splice into the relay grounds. and on top of that the stock setting will still work just incase you ur wiring goes bad or comes lose.

i just use a manual in car switch to control the passengers side fan and i just use the stock drivers side turn on temp for back up.

good luck.

 

Use the factory relays and wiring. I have tried all the methods and this by far is the best. Besides beeing safer, it is easy to wire and will work fine. Like Md said, wire the pri relay to a body ground, with a swich if you like, and then do the same with the AUX. Therefore you don't need heavy guage wire or switches as compared to a new circuit that would run power to the switches. I had that. It was a PITA, and did blow fuses. Grounding relays is the best method IMHO.

 

Are both relays the same? Mine were moved by a previous owner and I have _no_ idea which one is which or which one could be bad.... or which one to order....

 

Both relays are the same, GM p/n 14089936. Most of the relays on the car are these. I am not sure about your car but the relays should be on the p/s in the corner with the rad support and fender. You have either the batt or the charcoal canister there. The one on the fender is the AUX and the one on the side of the rad is the pri. I'd change both if you're uncertain of their origin, they're $10ea, and now you will have these as a constant. Then just wire the switch(es) as per the diagram found on this site.