ls1nova71

iTrader: (4)

Been trying without any luck to get my A/C to work through the PCM. A little info to start off with, I have a 2003 Silverado 6.0 4l80e with DBW which has the A/C that's turned on through the serial data line. I needed a 12v A/C request, so I rewired the harness like a 2005 Chevy Express van 6.0 4l80e DBW which has the older style 12v A/C request. I had the PCM tune changed to the 2005 van, but the A/C won't come on. I can command it on with a scanner, so I'm reasonably sure it's wired correctly, but sending 12v to the C2-17 wire on the PCM does nothing. Even the guy doing the tuning says there's no reason it shouldn't work, but it just doesn't. Anybody been through this??? Any help would be greatly appreciated.

As a last resort, I guess I'll have to just use the 2 pressure switches and try and bypass the PCM all together, but really would like to try to avoid going that route.

ls1nova71

iTrader: (4)

Nobody? Well at least I don't feel stupid for not being able to figure it out myself.

CalEditor

iTrader: (1)

what kind of tuning software is being used?

ls1nova71

iTrader: (4)

Tuner Cat I believe, and HP Tuners.

CalEditor

iTrader: (1)

Try the Monodax forum

Jones'n

Did you run C2-55 to ground, or preferably through a low pressure switch?

ls1nova71

iTrader: (4)

Ok, this may be a dumb question, but what is the Monodax forum?

Yes, it's grounded through the low pressure switch just like the wiring diagram shows. And if I manually ground C2-43 it comes on. The PCM just isn't grounding it.

CalEditor

iTrader: (1)

http://www.monodax.com/forums/

Do a search for AC or post a question. This is a TC/JET/Monodax forum

aknovaman

iTrader: (7)

Eric,
Monodax is the Tunercat for OBD2 forum. I'll post over there and see what we can get. I sent you two PCM's yesterday '04 and '05. I'll come over soon as I can and see what we can figure out.

CalEditor

iTrader: (1)

https://ls1tech.com/forums/conversio...cm-turn-c.html