Hey thanks! Shorted the LP switch, and the compressor started working. I wanted to see if any bubbles where in the slight glass, but was worried to run it if its low on pressure. If I run it will it cause any damage to the system?

I assume that the system is running on R12, as I've never had it refilled since new, and that was in 1985!!

Does this deffinatly confirm that the system is out of refridgerant? what else can I check?