LS88FoxBody

iTrader: (2)

I'm looking for a pinout for a 12576106 PCM . I reflashed the computer to a 04 GTO Tune.... The PCM was from a 03 GMC Yukon.

I can't figure why I can't get the fan to turn on. Looking for what pin , so far I saw two pins on Lt1 Swap... But no luck... I'm using the computer to flip a relay to turn a flew a lite syclone fan...

Frost

iTrader: (45)

You know the PCM will ground it's output right?

fastgmc98

iTrader: (15)

Negative Trigger on relay for fans...

jimmyblue

iTrader: (11)

If you're already using a fan relay, I recommend buying
an encapsulated, 70C/160F thermostat from some place
like Digi-Key and epoxy it to the radiator outlet neck,
and let the fan run based on actual rad (not block) temp.
Keep the rad below block temp and you have some "cold
reserve" for the thermostat to work with during surges.

LS88FoxBody

iTrader: (2)

So test light on #42 and ground , turn fans on in vcm scanner test light lights up . but when off light is still on just kinda dim...

gofastwclass

iTrader: (2)

I never use a test light on anything digital or computer related - even if it is supposed to be on / off. I prefer a DVOM for testing, especially because it tells you the voltage (and other things) on a circuit and won't damage something sensitive by placing a load on what you were trying to read.

Frost

iTrader: (45)

The PCM uses a small voltage to 'examine' the fan relay's coil for integrity. That is why you see a dim light.