A/C idle speed Q's

[kroberts]

I need to revisit a topic and could use some advice.

My idle speed has been cycling or surging when I turn on my A/C. I did a little troubleshooting today and determined that I have evidently mis-wired my up-idle circuit.

I'm running a red label 413 DME. Are these assumptions correct...

The DME increases idle speed when it receives a signal telling it that the A/C is on.

The DME receives this signal through pin 64.

Signal input is 12v.

Help me with these questions...

For troubleshooting purposes, if I make a jumper and connect pin 64 directly to the A/C compressor terminal, should this engage the idle speed increase?

Will this fry anything?

If those of you running AC on your swaps would like to offer some advice or tell my how you wired yours, I would appreciate it. Please use small words, I'm really weak with auto electronics (think 11 year old kid)

Actually ANY constructive input would be appreciated.

TIA

[7pilot]

What year M3?
what engine harness?

For a 1991 MY it is a white wire with blue tracer that enters directly into the DME loom a few inches from the DME plug of the s14 loom. The connector is behind the glovebox near the DME.

My experience is with a late 94 vanos harness which had X20 pins 4 Bk/Bl, 6 v/Gy serving the A/C compressor control relay and the A/C Temp control Module.

Other years of M3 may be different. My pin assignments did not match anything published on the web.

I never found the exact wiring codes for my M50 harness on ETM either, so you'll need to do some looking at your specific example.


m

[kroberts]

Car is an 88. Wire harness is for 1995 325.