AC idle up issue.

[slow_hemi6]

12v to the compressor triggers the electromagnetic clutch. For sure you would get a sizable spike from that. My fords factory wiring has a diode on that wire up near the compressor.

[Matt Cramer]

You can bench test the input on a JimStimX and see if the port indicator turns on and off.

[ducman82]

and if no signal is accepted. how do i fix it? is there a common component that goes out?

[Matt Cramer]

You'll need to follow the signal through the MS3X and see where you're losing it. If you're really unlucky, it may make it all the way to the processor. If that's the case, the processor has a damaged input port.

[ducman82]

decided to use a relay, and just use Launch IN as a ground switch from the AC compressor signal.. works like a champ!