01 suburban, fan swap

Hello all, now that I got my remote start system working properly I moved on to the electric fan swap to replace the belt driven clutch fan. The primary reason for doing this is to improve the performance of the AC when the truck is idling at stoplights. Houston heat can be unbearable.

Vehicle: 2001 Chevy Suburban 2500 4x4 6.0 (6.0 has been replaced with 383 built stroker motor).

Here is what I purchased:

1. New fan assembly for an '05 tahoe. This is a direct bolt-on for my truck.

2. Nelson performance harness to control the fans.

3. PCM tune from blackbear performance. I met Justin in-person today and he "turned on" my PCM for the fans.

I mocked up everything with a switchboard and verified that the harness and efans work as they should. Both fans on low when the pin 42 input wire is grounded, and both fans on high when 12V applied to the AC input wire.

But of course, as with everything else electrical related with this truck - there are big problems! Even something this simple just won't work. The truck will not control the fans at all...

1. I can't get the AC wire to trip the relays. I found a GREEN / WHITE wire that is 10V with AC on, but it won't run the relay! What wire should I be using for the 12V AC signal?

2. Pin 42 of the PCM will not turn on the fans. I let the truck idle for 20 minutes (without the fan clutch), the dash temp gauge read 240F and the fans still didn't turn on! How do I verify that the pin 42 is doing what it is supposed to? (I did verify that the pin is seated properly in the PCM)

Thanks for any help.

Matt



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2001 Suburban 2500 4x4
2006 Magnum SRT8

It works now...

I let it sit overnight and now it works. I didn't do anything different, sometimes this truck is crazy like that.

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2001 Suburban 2500 4x4
2006 Magnum SRT8