electrical fan wiring and such question.......

I need to power a fan for a heat exchanger and also run power to a 12v pump for a air/liquid intercooler. Where is the best place to get key on 12v power from on the car and should I run relays and where can I get some relays?

thanks!

Mark,

Get "ignition on only" power from the starter relay. Yes you will need a relay for the fan and the pump to avoid running high amps thru the switch.

Standard 30 AMP automotive relays are avalible at Autozone or any other national chain.

David

definitly use relays. if not you could start a fire.
joe

Here is a easy way to install it.

Standard ISO relay will have these terminals on it. 85,86, 87, 87a, and 30.

Connect the 86 to a switched ignition source at the fuse box. Radio should do the trick.

Connect 85 to a switch and connect the other end of the switch to ground.

Use 87 for Battery + fused of course.

Use 30 for the output to the fan and pump.

If you have "popping" through the radio when you turn it on and off, add a 1N4001 (available at any electronics parts store) diode across the 85&86 terminals with the band closest to 86, this will shunt the collapsing magnetic feild to ground and eliminate the popping.

Jeff