94 Voyager A/C Clutch problem

[shimfizzal]

Recently bought this vehicle. Although the air seemed to work well, as I started to run over everything I found the compressor wasn't cycling. Quickly found that someone (dealer?) had shorted the relay so that the compressor was always on. Clutch didn't engage with the relay in there without the wire(used to short the circut closed) so I replaced the relay. Seemed to work but next morning same problem. I opened the distribution box and confirmed good connections and also place a bit of di-electric compound into each female connection on the bus. Again, seemed to work but after running the vehicle, turning it off, and trying to start it again after a while compressor was still not coming on.

checked the high and low pressure switches which are apparently preforming correctly as well.

However, I did notice that this last time that the radiator fan was not on when starting up (with compressor switched to 'on'). When the system works properly (which is indeed intermittent) the fan is on and everything cycles correctly including the radiator fan.

I'm now wondering if the clutch relay is not juicing up becuase the radiator fan is not coming on.

Questions:
1. Which radiator fan speed is turned on for the a/c system, low or high?(would help to know to look at those parts of the circut)
2. Are there any components I have neglected to check that might be related?
3. If this is related to a faulty PCM wouldn't the problem be 'all the time' and not intermittent?
4. Is there a way to test the PCM without a dealership?

Thanks for any insight you can give on this problem