[This is a '95 Town Car with EATC but same basic wiring as a Vic.] I've been reading through the threads and seeing a lot of people have their A/C compressor clutch stop working. I was hoping (and praying) mine would be a common issue. But, unfortunately, I ran the diagnosis and found I have power to the cycling switch and relay center, but there is no power at the connector for the compressor clutch.

So, there is apparently an open circuit somewhere between the relay center and the A/C compressor on the front of the engine. With access really tight, I can barely see the connections and harness, much less reach them to do much work.

When I encounter open or shorted circuits, I typically run a bypass by making a new harness. To do that here, I would need a spare compressor clutch connector because I can't effectively get enough access to even cut off the old one and safely tape it up.

Also, there is the matter of the diode that must be incorporated into the harness.

So, does anyone have any info on the compressor clutch connector and diode? Is there a source where I could buy a NEW connector and diode? If I get a used one, it may be old and corroded. I suppose I could replace the internal pins if I can find the correct ones.

Any info on the connector, pins, and diode would be extremely helpful and greatly appreciated! With Winter weather just around the corner, I'll need the compressor running to help keep the windshield defogged on wet days (and we have a lot of those around here).

THANKS!!!

I just found this connector -- looks like a great source for replacement electrical parts:

http://www.repairconnector.com/index.cfm/fa/items.main/parentcat/25782/subcatid/0/id/419389

Now, if I can just find a suitable diode, I should be able to make a jumper harness. Thanks!

In case anyone else out there needs it, the factory part is still available. Cost is about $9 and the info is as follows:

Part Number: F2TZ14A604A
Description: DIODE ASY
ADP: F2TZ*14A604*A
Rey-Rey: F2TZ-14A604-A

later crown vics do not have a diode inline with the a/c compressor feed. so you should be able to jump across the diode with a peice of copper wire without problems.

that compressor connector you're after is also avaliable from your local ford dealer as a repair pigtail too. here's the motorcraft pigtail parts catalog for reference:

http://www.p71interceptor.com/motorcraftpigtails

are you sure that the wiring harness for the compressor clutch is the actual cause of your problems?

worn down metal clutch plates & an open in the compressor coil windings can also cause similar symptoms.

did you try pulling the connector on the pressure switch on the dryer tank and jumping a wire across the connector?

Like I said, I checked for voltage all the way through the system. I had voltage at the relay center which is *after* both the low pressure and high pressure cutoff switches. (This is where the PCM interrupt relay is located. It is easier to check there than at the high pressure switch.)

The next stop after the relay center is the compressor itself. I could measure no battery voltage there, indicating an open circuit.

Of course, I may not have been able to get a good connection because I could barely fit my hand in there to even remove the connector. Once I have a spare connector and diode as a jumper harness, I'll know for sure. Then, if it still doesn't work, I'll know there is a problem with the clutch gap, clutch coil, etc.

Thanks!

PS I checked my '05 wiring diagram for Vics/GM cars and it does show a compressor clutch diode. Only, this time it does not appear to be installed in the same place as on older models.

The connector for the A/C clutch coil ('05 models) is C100. On my car, the diode is inline in the harness several inches up before this connection. On the '05 model, it is wired into a branch circuit instead.

Rather than being directly in parallel with C100 in the same harness, this branch circuit goes back to the Battery Junction Box where the diode is located and it is grounded there.

So, it looks (at least at first glance) as if the diode wasn't eliminated, but moved to a different place on later models.

It's also interesting to note that later models break out the compressor clutch relay from the EATC -- which is where it used to be located -- and now mount it as a standalone relay in the Battery Junction Box. I guess this solves the problem of the solder connection failing on the circuit board over time.

But, the main reason is the PCM now controls the A/C compressor clutch on newer models rather than the EATC module. There is a new sensor that monitors A/C line pressure and also a sensor that keeps the evaporator core from freezing up and these are monitored by the PCM instead of the EATC.

It appears the vehicle's systems are being more and more tightly integrated with the PCM, making it harder than ever before to modify/customize to taste.