Electric Fan Conversion Question

Dantheman-2003 said:

I’m in the process of electric fan conversion on my 03 Tahoe. I pulled the factory harness off my 05 Yukon. From what I can tell, I have thick blue/black and yellow/grey wires going to fans. Red for power. The 2 small wires blue and green go to PCM pins.

Question is, where is the black ground wire that bolts to frame? I never saw one as I was removing this.

Any thoughts would be appreciated!

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The factory fan harness grounds the fans on the frame rail behind the driver side front bumper.

Where did you source your fans from? I'm looking at RockAuto and they don't seem to have a OEM fan assembly. My plan is to buy part from 2005 1500 Silverado catalog for my 2001 Tahoe... Unless there's a better part to spec.

Matthew Jeschke said:

Where did you source your fans from? I'm looking at RockAuto and they don't seem to have a OEM fan assembly. My plan is to buy part from 2005 1500 Silverado catalog for my 2001 Tahoe... Unless there's a better part to spec.

View attachment 442711

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I've read the newer model fans are better as they have more blades for cooling. K5L maybe? Pretty sure @Doubeleive has alot of knowledge on this subject.

Tonyrodz said:

I've read the newer model fans are better as they have more blades for cooling. K5L maybe? Pretty sure @Doubeleive has alot of knowledge on this subject.

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700w motors on the k5l vs 500w on the standard, fan blades vary.

These are the fan motors for K5L (Enhanced Cooling Package).

GM 15-81697 (Right)(700w; 5 bladed fan)
GM 15-81696 (Left)(700w; 5 bladed fan)

15780789 is the older 7/9 bladr K5L 700w assembly. Got mine on eBay. Seemed to work better than the newer 5/5 blade 700w for me in Texas summers at idle. They all have a significant draw. Need at least the 145a alternator but more is better.

Matthew Jeschke said:

Where did you source your fans from? I'm looking at RockAuto and they don't seem to have a OEM fan assembly. My plan is to buy part from 2005 1500 Silverado catalog for my 2001 Tahoe... Unless there's a better part to spec.

View attachment 442711

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I converted my 04 2500 sub to e-fans. I sourced the fans from junkyard. Pulled the fans and harness from same vehicle. Split the forward lighting harness apart and grabbed the OE complete fan harness with factory fuse/ relay blocks. If the fan motors later go bad, you can source just the motors and blades. No need to buy a complete housing assembly.

Currently I have 2 harness in the sub, the oe for when I get the ecm programmed. Its stubbed out ready to go.

The second harness is out of an 2006 to 2010 Impala police car. It uses external relays and power source **** fuses. I currently have both fans wired through two relays not three. They both are wired for high speed only and through the ac request signal. So technically they will only operate when the the compressor is on. I know its not the correct way, but it works.

mattbta said:

15780789 is the older 7/9 bladr K5L 700w assembly. Got mine on eBay. Seemed to work better than the newer 5/5 blade 700w for me in Texas summers at idle. They all have a significant draw. Need at least the 145a alternator but more is better.

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So KL5 cooling fan package from a GMT900 chassis? Fitment is the same on GMT800?