kainedogg

iTrader: (23)

Tossed an ls in my c10 with an Ebay top mount R4 compressor setup. Truck originally had ac. I am using a 94 S10 compressor lines, filter and accumulator.
It seems to have everything else. (Evaparator, box)
I can't find the ac clutch activation wire any ideas. Is this a workable setup?
Anyone have a similar setup?

Pocket

iTrader: (22)

The old R4 systems were ridiculously simple with two pass/fail switches

12v came from the HVAC head unit, commonly named "AC request"
From there it hit the low pressure switch, then to the high pressure switch on the back of the compressor. If it was over/under pressure, those switches would open and the compressor not engage
After the switches its to the diode to prevent feedback when shutting down the system and finally to the clutch. Simple ground to complete the circuit

These are favored when doing a carb conversion because they are independent of computer control. You can however add PCM feedback by tapping into the 12v wire after the high/low switches and before the diode. PCM AC compressor, not relay or AC request. This will bump idle speed when the compressor comes on, but itsnt required

kainedogg

iTrader: (23)

Thanks Pocket. Now I have more questions. I initially thought I only needed the "AC request" switch hook-up. Apparently I also need to hook up the high pressure switch on the rear? Do you have a diagram for where both switches integrate into the harness by chance?

Pocket

iTrader: (22)

http://www.austinthirdgen.org/mkport...F_and_vin8.jpg

Different ECM, but same basic schematic. The LS PCM pin will be for AC compressor, not AC request or relay (varies with year and PCM used). Its just a feedback wire to bump idle with it engaged. There isnt any PCM control, only hi/lo switches. Use this on carb application or any LS EFI swap

kainedogg

iTrader: (23)

Thanks Pocket. I appreciate it.