Bought the BP AUTO DIY harness some time ago. Been working on the truck for almost 3-4 years. I couldnt determine how I had wired the truck so far back and was concerned AC wasn't done correct so pulled it all apart.
Here is a pic of the wiring as it comes for the BP auto harness.
The problem is that the FAN#1 has a smaller gauge green wire that is going to the engine harness ..... assume that is the signal (ground wire) received by sensor/ecm.
The blue (Fan#2 ) does not. The smaller gauge wire is free floating once it leaves the BP harness.
Is this due to my original donor vehicle only having 1 fan ? (2007 Hummer H2) and 1 wire control.
How would I go about making the 2nd fan work.
I want the 1st fan to control the radiator fan.
The 2nd fan I want to control the AC condenser fan with a binary switch (so always on as soon as the switch is enabled in cab).
The original instructions only say
Engine Connection Wiring Guide
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** Dark Green - Fan1 Relay Control - This is the signal wire from the ecm/pcm that turns on the the low speed or first stage cooling fan. This is a ground signal.
**Dark Blue- Fan2 Relay Control - This is the signal wire from the ecm/pcm that turns on the the low speed or first stage cooling fan. This is a ground signal.
Chassis Connections Wiring Guide
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Dark Green 12 Gauge - Fan 1 30A - This is the 12v feed to your low speed or first stage
Dark Blue 12 Gauge - Fan 2 30A - This is the 12v feed to your high speed or second stage