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71meangreenc10 · 06-02-2015, 04:48 PM

My 2 cents.

I have done the MOD and here is what I have found. I have AC also and wired in a pusher fan on the condensor. When you hit the AC, both my fans kick on. With the AC on, lights on, HEI, fan at full speed, I measured about 62 (will have to verify that again, may have been 22) Amps with a Amp Clamp on the Alt. My Alt is from a 92 GMC so it puts out over 100 AMPS. If you decide to put in a 100 AMP Alt, ensure you check the red wire that goes across the radiator to the battery for over heating. I found mine by accident and it was really hot, I upgraded the wiring to either 10/12G wiring and no more issues. I have good grounds and a lot of newer wiring, so there was no corrosion build up in the wiring.

I can get you the part number for the adjustable relay I used for the fan. It is a very nice piece from Summit and it allows you to add in other circuits if needed.

Smitty

06-02-2015, 04:48 PM	#11
71meangreenc10 Its a Truck Thing...... Join Date: Dec 2004 Location: Sierra Vista, Arizona Posts: 3,179	Re: How many amp Alt needed with Jeep fan mod? My 2 cents. I have done the MOD and here is what I have found. I have AC also and wired in a pusher fan on the condensor. When you hit the AC, both my fans kick on. With the AC on, lights on, HEI, fan at full speed, I measured about 62 (will have to verify that again, may have been 22) Amps with a Amp Clamp on the Alt. My Alt is from a 92 GMC so it puts out over 100 AMPS. If you decide to put in a 100 AMP Alt, ensure you check the red wire that goes across the radiator to the battery for over heating. I found mine by accident and it was really hot, I upgraded the wiring to either 10/12G wiring and no more issues. I have good grounds and a lot of newer wiring, so there was no corrosion build up in the wiring. I can get you the part number for the adjustable relay I used for the fan. It is a very nice piece from Summit and it allows you to add in other circuits if needed. Smitty __________________ 71 C10 283/3SPD Full Resto 71 GMC 1500 Sierra Grande http://67-72chevytrucks.com/vboard/s...d.php?t=518599 70 C10 Suburban Former military GSA truck. 72 Chevy Blazer 4X4, Sloppy Jo, Mountain Climber. Wife says no more trucks. http://67-72chevytrucks.com/vboard/s...d.php?t=707378 72 GMC 1 Ton Motor Home, wife said no more trucks until she saw this one. Gen 3 6.0/4L80E 4.10 http://67-72chevytrucks.com/vboard/s...d.php?t=761110 68 GMC Suburban was 3/4 ton, now 1/2.Wife shook her head 71 C30 Wrecker 71 C20 Scott-Bilt As weird as it gets..BB Cheyenne AC Truck 68 GMC Long Stepside. They keep following me home 69 C30 Former Motor Home, Flat Bed time 70 G20 Red-E-Kamp Conversion "I'm your Boogy Van" Last edited by 71meangreenc10; 06-02-2015 at 04:56 PM.