I don't want to get into a pissing match by any means here, but I would like to clarify a few points. The last we have heard from this individual (until this morning) was on October 8th wherein we clarified which two PCM pins are to be used for fan control.
The email we received today contained the following text:
Both pins loose ground when 12volts applied. Basically the pcm is bad. Ground is good until power is applied.
I’ve also lost communication with my bcm. I have no power to speakers, power door locks, power windows, 4wd, fuel gauge, oil pressure gauge or temp gage.
Went through all my grounds, all were good. DLC checks out ok. Fuses good, and battery replaced. Switched back old pcm from the 5.3L and everything works. So my diagnosis is the PCM is bad.
To get to the chase, 12V power is never to be applied to the PCM pins for fan control. The PCM drives the fans by pulling the appropriate pin(s) to ground when conditions call for it. That ground trigger is to be used to energize a relay which then supplies power to the appropriate fan, fans or additional relays. Fans must *NEVER* be directly wired to the PCM. That is asking for, at best, fried circuits, at worst, an electrical fire.
We would never instruct, suggest, encourage or even permit somebody (within our ability) to apply a 12V power source to a ground trigger or wire fans directly to the PCM.