87 300E, The compressor failed. I replaced it with a re-built from AutoZone along with new receiver dryer. Took it to a local shop to have it flushed, evacuated, and filled. They fill it 34 oz of R12 and it doesn’t cool. They tell me the gauges show no real pressure difference between low side and high side with compressor on and clutch engaged. Their summation was bad compressor (defects are rare, but possible) because the freon is not being moved through the system.

I get the replacement compressor; they install it and still no cold air. Now they tell me the original compressor has left debris all through the system clogging things up. I asked if any trash was visible during the flushing process. No real answer to that question.

Are there any electrical functions that could be preventing the cooling process if the clutch and compressor seem to be working? Clutch is definitely engaging, and I can’t imagine two consecutive defective compressors.

Could there be issues with the klima relay or other switches and relays? Or is my clutch engaging a sign that these are in working condition

Any suggestions?

Other facts
In dash push button controller less than 6 months old
Holds pressure, no leaks
Blower works fine