Questions and Answers

GMC S15 Sonoma A/C Problem Q. Hi Vince. I've got a GMC S15 Sonoma Pickup with a 2.8 liter V-6 automatic. It's been parked in my garage for over a year being started occasionally. I would run the A/C every time I started it to keep the seals from drying out. I'm putting it back in commission now, and the compressor clutch doesn't engage, and it's hot in Texas! It's still a R-12 system. Where do I start?

As a side note, could you tell me the pros/cons of converting to R-134a, or send me to a link where you may have already discussed it.

Thanks...

A. It may be an electrical problem but my guess is that it's low on refrigerant. If you unplug the switch on the accumulator and jump the two wires on the plug and compressor engages, it's low. Pull the jumper wire out. Now you will need to find that leak.

My guess is a bad front compressor shaft seal or a hose crimp leaking. There should be an oily residue around any leak areas. Now in my neck of the woods, R-12 is over $80.00 a pound! So I would be retrofitting this thing to R-134a.

This is not a do-it-yourself job! All the old R-12 needs to be removed and a few parts may need to be changed, like the accumulator and manifold hose assembly. Then you need to add special oil for R-134a and also have u/v dye added. Then a vacuum needs to be pulled on the system for at least 30 minutes.

I'm sure you don't have the tools for this type of work so I would see an A/C specialist.