AC will not engage idle control

[marty]

Idle control solenoid is working as turning on the headlights will energize it.  Manual is very vague about where ac input is, referring to the ac relay...which I have not been able to locate. 

[AMC of Houston]

I'm not sure the A/C triggers the solenoid at all.   Look at pages B-263 - B-264 of the MR251 manual.

[marty]

George,
  Thanks for the reply.  This is on the 83 Wagon.  Emissions bypass has been done on both the the 83 and 86 so the MCU is out of the pic.  The 86 engages the sol vac w ac, headlights or rear window defog.  Rear window defog is inop on the 83 but it used to work for both ac and Headlights.  In the 83 TSM, pg iJ-38 it says the holding sol is engaged if hl, ac or rwd are energized.  In the 86 TSM, pg B-301 wiring diagram, it shows separate wires fm the systems to the sole vac but doesn't show where they come from...wiring...agh!

[AMC of Houston]

Well, I just looked thru my '83 manual, and it seems the Sol-Vac power feed circuit goes thru some other CEC stuff between the A/C compressor switch and the solenoid (thru the CEC diode assy. & idle speed relay).   Since you did the bypass, that may be why it isn't working.    So you may want to just bypass that CEC stuff, and run a wire direct from the A/C relay to the solenoid.

[marty]

That is part of my problem...where is the ac relay?  Can't find a pic or description of the location!

[AMC of Houston]

This is a learning experience!   I think I got a clue (finally).   After wading thru more manuals, and checking my AMC parts books; I discovered that there is no A/C relay!!   Its simply the micro switch on the dash A/C control unit that triggers the compressor clutch circuit.

[marty]

Hmm, will have to try and trace the wire from the connector.  AC turns on so at least part of it is working!