Can anyone help me with an AC issue?

I'm at my wits end and I am running out of resources to tap into.....

new to me 1994 Chevy G20 conversion, front and rear AC, 60K original miles.....

I am not getting power to the compressor.
The pressure switch is good and is getting power.
If I jump the compressor clutch with a hot wire it'll kick on.

I cannot locate an AC clutch relay on the dang thing, I pulled the dash and dog house only to find hours of work fixing the PO's hack work but, no relay.

I've been all over the net, and the Chilton manual is useless.

Any help is appreciated.

 

Yeah, Chiltons and Hayes manuals are pretty much a thing of the past. When you bypass the switch at the compressor does the unit put out a good cold air? Any fluctuations with the needles? I was training to become an auto AC tech long ago but gave that up for a more lucrative job in the petroleum distribution and sale industry, and am not familiar with twin A/C evaporators as there were none then (something I intend to rectify) but its possible that your rear evap unit might be the culprit here. Are you positive that your pressure switches are operating properly? Has your G20 been converted to use R134A refrigerant ( I will assume it has or likely does use R134A)?