oakley6575

iTrader: (3)

I have a pair of Flex-a-Lite electric fans for my LQ4 408. The computer and harness is from a 2003 silverado. The fans came with a controller box that uses a probe thermostat. It sucks and is inconsistent.

My question is: how can I wire these fans to run by the PCM? I want them to run with the A/C system; turn on low speed when the a/c clutch is engaged. And I want them to run on high speed when cooling is needed. I know the 2003 trucks didn't come with electric fans, but there has to be a way to utilize the pcm's knowledge of the coolant temps, and have a signal be sent to the fans when they are needed.

PLEASE HELP

01ssreda4

iTrader: (96)

If the computer isn't pinned for a fan out then no you can't use it to activate them. The fans would have to have their own temperature controller. If it is able to control fans, you could figure out the pins numbers and use them to power your fan relays.

oakley6575

iTrader: (3)

The computer isn't pinned for fan relays. But I have read that some people use pin 42 as a fan control. I don't know if this works or not.... Can someone confirm this?

01ssreda4

iTrader: (96)

What is pin 42 listed as its function?

oakley6575

iTrader: (3)

It is blank.. So can the tuner tell the pcm to use it as a fan relay?

71LeMans

Were you able to figure out how to run the fans? I'm looking to do a similar set up..