a/c conversion questions

[r6z4o6]

According to my 1991 GM C/K Pickup Electrical Diagrams,

When the ignition Switch is in RUN, battery voltage is applied through the A/C-HTR Fuse(brown wire) to the coil and contacts of the AC Clutch Relay.

With A/C ON selected, Terminal 966(Dk Blue/White) of the Heater and A/C Controller is grounded which energizes the A/C Clutch Relay.

The contacts of the Relay close and battery voltage is applied(Lt Green) through the closed contacts and the normally closed A/C Accumulator Switch to the coil of the A/C Compressor Clutch(via Dk Green wire).

>>There is a junction here. The Dark Green wire *also* goes to PIN B8 [Circuit 59] in the '91 ECM labeled Air Conditioning)<<

The coil is energized and the A/C Compressor Clutch engages(when voltage goes out Blk wire to sheet metal ground).

sooooooo

ala Connector Part Information

A/C Compressor Clutch Supply Voltage [also Circuit 59, how fancy is that??] is STILL dark green..we are getting closer...

It is Pin 18 on the C2 RED connector.

[pnhigg]

Thanks a bunch for the info.
I am still not quite sure I am 100% sure, and it was probably the way I asked the question.
So if I connect (beyond the junction) one dark green wire from the 92 harness to the a/c clutch the other will go to pin 18 on the red connector to signal the pcm to increase idle rpm, or do I connect it to terminal 17 the a/c signal wire?

Sorry about redundant questions, I just don't want to fry my pcm.


Thanks again for the help, and the attached list will be a great help.

Patrick