hey guys, im gonna wire my flexalites to my pcm so it can control my fans that way. my vsc keeps kickin the dust on me. Seems like the blue number 42 is the wire to control that, but what is the second wire to control the second stage fan? i noticed that on ls1edit it has the capibility to run 2 fans so i was needing to know. thanks.

You can't use the secondary fan setup on the truck applications. This is because in the truck program the secondary fan control location is used to control an HVAC door or some strange thing.
To run multiple fans from the PCM, just use 2 relays and let them BOTH be controlled by pin 42.

John .. what about using the programming out of the 05 Chevy? Do they have an unused pin on the PCM for the 2nd fan?

just wondering if you can hook up a swith to turn the fans on and off when the truck is not running?

I kinda figured that was the case... thanks for confirmin that for me anyways. Looks like ill be workin on it tonight. thanks guys.

I just did the reasearch on that last week cause I just put in my 6.0 radiator with dual 16" Zirgo fans. On the f-bodys pin 33 on the red connector is the high speed trigger. Our 33 is HVAC rear door control. I dont even know what the hell that is. The cars dont have that at all. I was all ready to have the low/high speed myself. Guess I will have to think up something else now.

Does anyone know if pin 42 is triggered by the ac as well as the tunned temp settings? If not, ac request may be what I use for a high speed trigger and have the temp turn them on low speed. :dunno:

i just wired my fans, and pin number 42 didnt work. I tested my relay but using a wire from the relay to the battery as the trip wire, the fans worked great. however, when i hooked up to number 42, nothin. i let my truck idle till the temp was around 210. the set off tempreture in edit was at 180. i tried having it on the aux. fan setting as well as the 2fan setting. both did not work. any suggestions? btw, pin 42 had no wire so i had to install pin there. thankfully i got some extras so it was a piece of cake.

You do know it is negative triggered right.

If you can take the wire from pin 42 and touch it to the battery (+) and the fans work, you may have it wired up backwards. Pin 42 GROUNDS the relay connection when the fans are requested.

You have it wired right when you can take the wire out of pin 42, touch it to ground, and the fan(s) come on.

Relay position "86" should go to a key-on 12 volts, and relay position "85" should go to pin 42 of the PCM.