As the title says, I'm thinking about installing an IC Fan to turn on when the airpump comes on. I am planning to just tap the positive connection for the airpump, which switches on only at idle.

My rationale is that the purpose of the fan is to reduce IC heat sink while the car is not moving, sitting in traffic & at stop lights.

What do you guys think? Would I ever want/need to have the fan on otherwise?

 

Well......I dunno.

The airpump kicks off at about 3000 rpm or so, so you would be seeing an awful lot of on-off-on-off activity with your fan wired this way, plus I have seen the FD is not real tolerant of tapping into wires here and there. If you do go this route I would put a diode in line so that there would be no chance of any electrical feedback from your fan to the airpump.

Just my .02 worth.....

 

A good size fan will draw to much current for the air pump wiring. You could use the air pump to trigger a relay to the fan. Or just run a spst from a high amp key on wire to the fan. My mechanic has his lighted spst rocker mounted under the steering column .

 

Yes, I would definitely use a relay. The wire to the air pump just runs a clutch in the air pump, so I am not sure how many amps it can handle. It should be fine to trigger a relay for a fan, however.

I had mine hooked to the radiator fan relays, but I didn't wire it up correctly, so it would only turn on at high fan speed. You need to tap two relays, and use diodes so that they don't trigger each other after you add the wiring. My mistake was that I spliced into the high current wires, and they don't all go to 12V, so only one of the ones I tapped would turn on my IC fan control relay. What I should have done is tapped into the signal wires. I think it should work that way. Running them with the radiator fans seems like a good idea to me, since it would reduce heat soak caused by the radiator fans coming on.

I think I might wire them as I describe above, or use an external alarm signal on my SPA water temp gauge.

-Max

 

Thanks for the info guys. Now, I just need to research how to correctly wire the relay switch. Or maybe I'll enlist my electrician buddy to help out.