Black-Syde

iTrader: (7)

Ok I grounded the blue wire from the nelson harness with a switch. It works but they both come on at low speed. I haven't driven it but will it be better to have it come on with the fans on high speed? Just in case?

04BlackSilverado

iTrader: (6)

I got a DPST switch (it has 4 wires and acts like two switches in one) and had a tap off the AC wire on one side of the switch to +12v, and a tap off of the PCM wire to a ground. But you need to put a diode between the tap for the AC and the AC Clutch wire so you don't backfeed the clutch.
This will turn both fans on High anytime weather its cold or hot.

budhayes3

iTrader: (19)

Both fans on low should be fine, that's how mine works when it reaches temp and the fans come on. Normal operation of the harness/relay system is a follows: 1) reaches temp- both fans on low 2) a/c on- 1 fan on high 3) reaches temp w/ a/c on- both fans on high

Black-Syde

iTrader: (7)

Cool thanks for clearing that up. I just wanted to make sure.