Jaguar Repair: A/C Compressor Clutch 12 v not present, climate control system, ranco thermostat


Question
This is the last item on my rebuild of a 1985 XJ6.  The compressor was recently rebuilt. When charging the system I noticed that the compressor would not activate.  The system is fully charged.  I believe that the Thermal fuse located on top of the compressor is fine as I connected a wire from the +battery to the B position on the fuse and the compressor clutch activates and works fine.  working back from the thermal fuse what should I check next.  Although all the fuses in the fuse blocks look fine perhaps one of them is the cause.  Is there an inline fuse or circuit breaker.  It worked fine the day before I charged the system.  Perplexed.

Answer
Hi Kyle,
The climate control system in the Jag is complex in it's operation but you can check three fuses involved in the AC system, #6 fuse 35a in the main fuse box and #16 fuse 50a in the Aux fuse box and an inline fuse in the right side of the AC box behind the passenger's left knee pad. The fuse is a 10a fuse that connects the Yellow w/brown tracer wire from the Ranco therm to a brown w/yellow tracer wire from the fan control relay pack and the servo assembly. The compressor clutch wire (Green w/brown tracer) runs into the Ranco thermostat and the servo assembly.
If that don't show you what is wrong you need to get the Jag ser III manual as the tests for the AC system are too much to attempt to do via e-mail.
Howard