OK,

The compressor is cycling on for 2 seconds, then off for 4 seconds, repeatedly. The pressure on the low line will build to 45 psi, at which time the compressor turns on. The pressure quickly drops to 20 psi, at which time the compressor cycles off.

I have a recharge hose and a new can of r134a. I hooked those up, jumpered out the low pressure limit switch (blue wire to gray wire, BTW), after which the compressor ran continuously. I ran the compressor for about a minute, then hooked the limit swith back into the system, after which the compressor began to cycle exacly as it did before.

I left the r134a hooked up and let the compressor cycle for about 5 minutes to see if the cycle period became longer in duration - no change. I verified that gas was available at the end of the hose (cracked the valves and listened for gas).

I did notice that the recharge hose was pulsing with the compressor, as if back pressure were building in it and then relaxing. Also, the can of refrigerant is not getting cold - shouldn't it get cold as the fluid changes state to a gas?

My next stop is a pro to evacuate and recharge the system. How much r134a should go back into the system - does 1.65 lbs sound right?

Also, are there any other tests that I can make on system components to keep down the cost of repair? I did not see a sight glass on the receiver/drier to inspect the flow of the fluid for air bubbles - is there one? Where is the high pressure switch located?

Thanks for all of the help - my wife and kids thank you, too.
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Ten Sleep 1980 245DL 1995 850 Turbo 1997 Dodge Dakota 5.2L