Quote:
Originally Posted by chebyshortbox65
It’s possible I’ve been running a blue/green ecm for over 4 years with the pcm controlling the a/c compressor and fans. The programming has to be set up for it with hp tuners pin 17 blue connector 12v through high pressure switch. Pin 43 blue connector to a/c clutch relay to ground the relay. Pin 55 green ground through the low pressure switch. Pin 18 green connector 12v spliced in line with the compressor 12v supply from the relay output. Factory 03 up a/c transducer pin 1 transducer to pin 80 blue connector. A/c transducer pin 2 to pin 45 blue connector. Transducer pin 3 to 14 green connector. It’s a mix of f-body. 99-02 and 03-06 wiring.
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This is very interesting. Do you know what service number your pcm is? Do you have any idea exactly what was modified in the tune? Or how this works?
I'm trying to wrap my head around the wiring, because half of these pins aren't A/C related, and the link below shows that most blue/green pcms are missing the components required to recognize the 12v request signal. My understanding is that the BCM sent a serial data signal for the request in '03+ pcms, rather than the standard 12v request like '99-02.
Blue 17 = Signal B (A/T) Trans Fluid Pressure switch
Blue 43 = Fuel injector 7 control
Green 55 = Not used
Green 18 = Clutch start switch (M/T)
Blue 80 = Low reference (ECT)
Blue 45 = 5 volt reference (A/C)
Green 14 = AC refrigerant pressure sensor signal
For anyone who hasn't seen this thread yet, check it out:
https://ls1tech.com/forums/conversio...c-request.html