Adding a manual switch to auxiliary fan

I have a 2000 cherokee and I want to add a manual switch to the aux cooling fan. Is there anything wrong with splicing the positive fan wire to a switch and then running a ground to the other switch pole? Would this interfere with the automatic operation in any way?

Could I run the ground to the accessory negative outlet and be fine? Would this mean it would use the accessory outlet fuse?

Thanks

My bad about putting it in this forum, I had a few windows open

Hey Combatcm:

That is exactly what i did with no ill effects now I can control when the fan runs. they seem to run to hot before the aux fan kicks in.
sixer...

You'd be better served with using the switch to trip the relay tho, rather than the fan directly. It's an issue of switching a couple dozen milliamps than having to switch a dozen amps or so - easier on the switch, and you can get away with using smaller wiring.

If you wire the fan directly, use one size larger than the fan leads (brings you up to 12AWG, I think) to compensate for the longer run. If you just trip the relay, you can run 18AWG or 20AWG without any trouble - which is easier to handle...

I use a new relay, controlled by the new switch. Spliced in 12 B+ into fan hot. this is controled by the relay. This gives you what 5-90 said about low current draw across the switch, and puts the fan power in parallel.

DaffyXJ said:

I use a new relay, controlled by the new switch. Spliced in 12 B+ into fan hot. this is controled by the relay. This gives you what 5-90 said about low current draw across the switch, and puts the fan power in parallel.

Click to expand...

Every bit as good. Using a relay allows you to keep the main power leads short, and use a smaller switch. "Win freakin' win, baby!"

one of the best thing you'll ever do. i never worry about heat again.
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