'01 Escort A/C problem (usa)

My sister informed me that the A/C in her car was only working intermittently for the past two months until it finally stopped working all together one week ago. She had the local garage look at it and he said she
needed a new compressor connector with attached harness. She went to the dealership and was able to order this item. This to me was a big suprize as having been a tech for many years with Mitsu we were only able to get complete harnesses. Anyhow, the part is on order for $24 and her local mechanic said he would only charge $25 for replacement.
After she explaind to me this story I told her I wanted to look at the suspect connector/harness. Doing so I could find nothing physically wrong with it. Testing it with the vehicle running and A/C on showed a constant 12v on the Lw wire and alternating ground on the R depending on the switches ON/OFF position. This to me seems proper for a negative switched circuit. I also manually grounded the R wire while the compressor was being supplied 12v and noticed no compressor clutch engagement. To me this shouts out clutch failure. As I'm not familiar with Ford I'm hoping to solicit some backup here from those that have hands on experience with Ford electronics.
Any insight would be greatly appreciated. ;-)
Cheers, Tj
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If indeed you are supplying 12v to the compressor directly from a voltage source such as the battery, and not through the circuit itself, and the compressor doesn't engage, then the clutch is at fault.
But before you go out and buy a new clutch, check the clutch gap first. It should be between 0.18 and 0.80 mm, preferably the smaller end. The gap is adjusted by shims you'll see after you remove the center bolt. Remove a shim to decrease the gap. If there's only one shim, you can buy a shim kit from Motorcraft or the dealer, but only if you look for the part under the Taurus line. Or just find a similarly sized flat washer.
Besides the clutch gap, the most common problem with Escort A/C systems is failure of the A/C relay in the CCRM, a black box located beneath the air cleaner housing. Sometimes, instead of failing completely, the relay fail under load, so that you may see 12v at the compressor connector when it's disconnected, but once you connect it back up, the current fails to flow. According to the Ford manual, the CCRM is replaced as a non-serviceable component, but by following instructions at feoa.net, you can locate and replace the faulty relay for $10 instead of upwards of $200 for the whole unit.
Bob
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Thanks Bob!
Yup, 12v jumper directly from batt/ground to chassis. As I can superficially see nor smell signs of the clutch having recently been burnt either electrically or mechanically it very well could be as simple as excessive air-gap. Will check it and shim via your guidelines if warranted. Thanks for the info. ;-)
Cheers,
Tj

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