From what I understand, they generally do not cycle, but they will engage and disengage based on the opening and closing of the pressure switch.

Yes, if you are not getting 12 volts at the compressor, then the problem lies somewhere up the line. Also check your grounding cable. Poor grounding will cause all sorts of issues.

__________________
RRGrassi


70's Southern Pacific #5608 Fairmont A-4 MOW car

13 VW JSW 2.0 TDI 193K, Tuned with DPF and EGR Delete.

99 W210 E300 Turbo Diesel, chipped, DPF/Converter Delete. Still needs EGR Delete, 232K

90 Dodge D250 5.9 Cummins/5 speed. 400K

Gone and still missed...1982 w123 300D, 1991 w124 300D