just installed everything and was wondering... my truck was tuned when Chevy did the 6.0 swap with the prior owner... they sent it off but i have no idea to who but they dropped the speed limited and such stuff like that... my question is what are the chances of them turning on the fans? ive got everything hooked up... pins 42 and 33 plugged up and all... I was thinking i read that one of the fans should come on anyways when i cut on the AC... but i may have read that for the nelson kit which i see slices into a harness vs. using the pin 33 slot... i was wondering because i get no fan movement... more then likely because they didnt turn on the fans with the tune but i was just wondering... tunes coming next week and it doesnt run hot as long as im moving anyways so not to worried at the moment... just want to make sure that once he tunes it that its gonna be working right... thanks!

 

Yeah you gotta tune those in if its on both pcm pins im pretty sure.

 

i think so too but i would think anyone who tunes these would just always turn on the AC feature whether they use it or not... it doesnt hurt anything so i dont see why even GM didnt even do it...

 

IIRC your tune is set up for mechanical fan or something. I dont have efilive on this computer or I would look. Heck I cant remember. I know the other options are series or parallel . And gm didnt have electric fans in 04, so they had no reason for tune provisions.

 

The two pin harness should dictate the fans via ect (pin 42) and ac line pressures (pin 33?). The parameters must to be adjusted through the tune to work on a vehicle equipped with a clutch fan from the factory. The single pin harness uses pin 42 for ect controls as well as a wire spliced into ac compressor trigger wire that enables the fans when the wire is grounded by the pcm (engages the compressor clutch)