I turned on my A/C yesterday and it's not working. Before taking to a shop, I will attempt to troubleshoot the the problem.
The compressor clutch does not engage. From what I have read, it is:
A bad clutch.
No power to clutch.
Low on refrigerant/leak.
I have never dealt with A/C before. Does anyone have any tips one the best way to proceed?

 

I would begin by investigating the low-pressure possibility but unless you have gauges, the only way I know of that might give you at least a halfway-decent idea of what's going on is to attach a can of refrigerant to the system via one of those flexible filler things - but those aren't generally available for R12 systems in the marketplace anymore, you'd need to find somebody who's willing to work on an R12 and who still has that equipment.

Unless you've been converted to R134.......

 

It has been converted to R134. Sorry, I should have mentioned that.

 

If you have a voltmeter, you can probe around the pressure switch and/or clutch (depending on what you find) but you'd probably want to know the colors of wires to be probing... that information might be in the EVTM on Gary's garagemahal site, look through this manual and see what you can find:

EVTM - Gary's Garagemahal

Or, you can go buy a can of refrigerant and one of those one-time-use filler dealies and add some refrigerant and see what the gauge on that thing says.

 

I purchased a can of refrigerant. I put it in. It's cold!

 

I hope the gauge (hopefully your filler-dealie had one) showed a reading in the OK area; undercharging is bad and so is overcharging.

One is supposed to add refrigerant by net weight of the stuff but that's hard for the average home mechanic to do, so pressure in the system is used as an approximation.

 

Yes, I used a gauge. Thanks!

 

Good deal!