Air Conditioning problem
1988 Ford Thunderbird V8 Two Wheel Drive Manual 57000 miles
----------------------------------------------------------------
I have a 1988 T-bird, the AC system has been converted to R-134a. It started working intermittently on my last trip from work, sometimes cold, the just vent air. I put gauges on it and the charge is ok, but the clutch only engaged a couple of times. Now it does not engage at all.

The clutch connector has 11.5V on it when the AC is turned on. I jumpered the clutch to the battery, and it engaged, the ac was cold like it should be. Where do I start to find the problem?