This AC project of mine has gotten rather challenging and I could sure
use some feedback from anyone familiar with AC systems.

Here's what I've done so far:

New compressor
New drier/receiver
New expansion valve
Flushed system with AC flush solvent
Cleaned evaporator and installed new foam filter
New O rings at all opened connections
Reconnected all fittings
Pulled a vac and let it sit for an hour (no leaks)
Charged the system to spec
Fired up the engine and turned on AC

Results:

Compressor works, but rad fan is not coming on. After a few minutes,
the high-side pressure is way too high and the compressor is not
cycling.

Trouble-shooting:

Pulled all associated relays and fuses. All tested OK, but could not
figure out how to test the more complicated AC relay. Tracing the
wiring to the rad fan, I get no voltage from the AC relay to rad fan
resister block. Also, looking at the resistor block, there is a chip
of ceramic that was missing which left a portion of the imbedded wire
exposed. The rest of the block had lots of little cracks. Not sure how
to test it although there was continuity between all terminals.

Conclusion:

I suspect the AC relay is bad. This could be the reason for rad fan
not coming on when AC is turned on. If the rad fan is not running, the
condenser heats up and can drive the high-side pressure above normal.
Replace rad fan resistor?

So, am I on the right track here?

Thanks in advance for any help.

Keith O.
90 Westy Syncro "VikingWagen"

PS Please CC my pmail, I'm on digest mode.