Is there a way to "hotwire" my A/C to see if it works? I disconnected the heater control valve so , no heat. 1985 190D

 

Since I found out myself, I'll post the answer in case someone searches for this topic.
On the compressor, applying 12 volts to the #3 wire (blue) will engage the clutch.
QTBAND

 

an easier way would be to bridge the connector on the receiver/drier.
process is to disconnect the connection, bridge the connection (a paper clip works fine). that will give continous power to the compressor to make itengage. at that pointit will be easy to add more freon