2002 gt AC inop

How to troubleshoot AC clutch & CCRM

Let's start first by confirming ALL of the fuses. Check fuse F1.24, F2.2, F2.23, and F2.24. F1=Battery Junction box (BJB). F2=Central Junction box (CJB).

Note, it can sometimes be hard to tell from above if a fuse is actually blown. Recommend pulling the fuses one at a time and checking with an Ohm meter (or visually).

Power to AC clutch can be interrupted at the fuse, the Mode control switch in the passenger compartment, the AC high pressure switch, the AC low pressure switch, and the CCRM. The PCM will also disable the AC clutch during WOT.

Note, on the GT models, the AC clutch is grounded via the CCRM at G101. So if trying to jump the AC clutch for a functional test, it will be necessary to supply both +/- 12 volts directly to the clutch. It may be difficult to get to the connector. Once done, it will be easy to hear/see the clutch engage. The engine does not have to be running. In fact, best that the engine is not running as the area by the AC compressor is difficult to access.

IMO, it is possible to burn up the CCRM if +12 volts is forced backwards via the grounding path through the CCRM. The polarity does matter. So be mindful of this if probing leads with everything still connected.

If the AC clutch is good, recommend testing the CCRM next. The CCRM can be difficult to access. Usually requires removal of the Right hand front wheel fender liner. It will be easier to access the different test points once you have easy access to the CCRM.

Please review diagram 54-2 and 54-4 in post #2. The diagram will give the terminal numbers and wire colors to aid in trouble shooting.

http://www.stangnet.com/mustang-forums/817829-c-not-working.html

Sounds like you are making this MUCH harder than it has to be. Most autoparts store will sell an affordable re-manufactured unit. The re-manufactured unit will come with a warranty as well as a guarantee to work.

BWD - Relay Module
Part Number: RCM12M

BWD RCM12M - Relay Module | O'Reilly Auto Parts

Everco/Cooling Fan Control (37514) | Cooling Fan Control | 2000 Ford Mustang GT 8 Cylinders X 4.6L SFI SOHC | AutoZone.com

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Relay Control Module
Product Line: NAPA Reman. Computers
Part Number: NEC XTP370012
Price: 98.99 (core)

For the salvage yard option, try car-part.com. Note, Ford uses the same CCRM in a ton of different cars so it does not have to come from a Mustang. Use the Oreillyauto compatibly tab to find other possible donor cars.

My CCRM went out earlier this summer. I bought the A1-Cardone one from O'Reilly Auto Parts (as per WMBurns recommendation) and it has worked flawlessly since. Comes with a 1 year warranty as well. Be sure to get the one for your specific year model. They ARE different from year to year.

Hey I have a similar problem I recently swapped engines from a 99 gt to an 02 gt I swapped the PCM ccrm PCM wiring harness ignition lock cylinders and cluster everything works fine except the cooling fan runs constantly with the key the rear window defroster stays on all the time even with key off and the ac compressor clutch stays engaged. It was draining my battery from full charge to 0 volts in 10 minutes. I pulled the rear defrost fuse in the Battery junction box and the ccrm 20 amp mini fuse also in BJB I think it controlled the ac clutch. Any ideas on how to fix the ac? I don't care about the rear defrost.

My gut tells me that the PCM, CCRM, and wiring harness are not playing well with each other.

There are small differences between the model years.

This problems perhaps is be more complex than someone out in Internet land can solve off the top of the head. This may require someone to get the wiring diagrams from the different Model years and compare the connector pin outs to each other. The key factor is the exact combination of source MY for the wiring harness, PCM, and CCRM.

Recommend going to ebay and purchase a Ford service CD. This will get you access to the detailed wiring diagrams. The cost should be less than $25.

Optionally, go to Alldatadiy.com and sign up.

Good luck.