I have a 2003 town and country and the a/c compressor isn't
Kicking in. I have no power at the clutch. I have tested And have power at the relay, what is the clutch suppose to have
When you ohm it out? Could the clutch take out
The PCM?

 

No spec really, just look for continuity. You should have power at pins 86 and 30 with the ignition switch on. Fuse 18 is power for pin 30

There is a zener diode inline that should prevent that

 

Where is the power to 86 coming from?

 

Ignition switch feed to the IPM. It's internal. A bunch of other terminals in the IPM use that feed once it gets into the IPM

 

Is 85 power coming from the dash control, and 87 going out to the compressor?

 

87 is power to coil. 85 is the wire that PCM grounds to energize the relay. There is no direct power from control head to compressor. The PCM has complete control. It reads a bussed input from the control head via the BCM, looks at the high side pressure sensor and the evaporator fin temp sensor and makes the decision to energize the relay or not to....and for how long
of duration.

30 to 87 is the controlled side of the relay. 85 to 86 is the control side..or the "magnetic coil" side. When the relay coil ground is closed (the PCM closes it internally) that pulls the contacts closed between 30 and 87 which sends power to the compressor.

There are almost no switches or buttons on your van that actually do work or route power. They are all request signals sent out over the communication bus network, and the control modules control the routing of power feeds.

 

What is the easiest way to get at the evaporator fin temp sensor?

 

Take the glove box door off. It's a 3x4 rubber cover with wires going in it. Now, some vans had a thermistor on the expansion valve instead of a fin sensor. If the expansion valve does not have an electrical plug on it, then you have a fin sensor.

 

I put my alligator lead on my battery and other end on test light and the compressor has power that way. What is that telling me?

 

That the compressor coil/clutch does not have an open circuit and the ground is ok.