Connecting aftermarket cooling fans to alternator.

[mauibarber]

My high amperage cooling fans are currently wired up to the positive battery terminal.  I want to run them off my alternator side.  Where do I tap the power from the alternator side?  Would it come off the starter relay? 

I have SPAL fans and I can't find anything on their site about wiring them to the alternator.
www.rondavisradiators.com/Spal%20fan%20wiring%20instructions.pdf
-Alex

[elacruze]

Follow the Alt. wire. Wherever it ends, you can attach. Theoretically you could attach directly to the back of the alternator on the power stud.

[mauibarber]

The alternator wire connects to my starter relay.  But my positive battery terminal also goes to the starter relay.  Won't tapping into this still pull the needed power off the battery side and not the alternator?

[2Gunz]

There isnt a "side" if you have bypassed the Amp gauge which you have.

Connecting it to the ALT stud or to the battery or anyplace along the way will all equal the same thing.

Your only worries are....

Is the alternator big enough to charge the battery with the fans on?

Is the ALT wire size large enough to support the added draw?


And whatever you do make sure you add fuses to whatever you add and put them as close as you can to the SOURCE of the power.

[elacruze]

There isnt a "side" if you have bypassed the Amp gauge which you have.

Connecting it to the ALT stud or to the battery or anyplace along the way will all equal the same thing.

Your only worries are....

Is the alternator big enough to charge the battery with the fans on?

Is the ALT wire size large enough to support the added draw?


And whatever you do make sure you add fuses to whatever you add and put them as close as you can to the SOURCE of the power.

[Nacho-RT74]

There isnt a "side" if you have bypassed the Amp gauge which you have.

Connecting it to the ALT stud or to the battery or anyplace along the way will all equal the same thing.

Your only worries are....

Is the alternator big enough to charge the battery with the fans on?

Is the ALT wire size large enough to support the added draw?


And whatever you do make sure you add fuses to whatever you add and put them as close as you can to the SOURCE of the power.

+1

Since you already bypassed the amp, no matter where you take the power, but you need to pay attention on the fans consumption and alt output.

well In fact the closer source to feed the fans relay it is already the alt

If the alt is good enough won't charge the batt ever, just right after the starting for a few minutes, from there just will feed the car demand. Thats the main goal on everything, so you don't really need to think on feed the fans AND charge the batt, simply feed the fans and KEEP FEEDING without any decay on power, the rest of the car demand.