1992 Accord A/C Issue

Greetings!

I’m driving a 1992 Honda Accord 4cyl, MT, 167k miles, with no air conditioning… I’d like some guidance and/or pointers on how to fix my A/C; the relevant car and troubleshooting history is as follows:

I bought this car last fall, and the seller of the car told me about, and showed me receipts for, a complete repair of the A/C system including a new compressor and a retrofit from R-12 to R-134a. Two shops, a retrofit and bypass switch for the main A/C switch, a compressor, a junkyard ECM and junkyard HVAC controls set later, the seller sold it to me as a working system. I didn’t check it as well as I probably should have – it was November after all when I bought the car.

But in the time since, I managed to get the compressor to turn on one time a couple months ago for a short time – I didn’t get much cold air because as I discovered a couple months later (a month ago from now) the system was very low on refrigerant (tested by a quick poke of the low pressure schrader valve). Although I realize you have to take static A/C pressures with a grain of salt (my compressor wasn’t turning on at all last month), I first suspected a low pressure lockout, therefore I used a refrigerant can with a gauge on it to put more R-134a in, being careful not to exceed the pressure caution zones on the gauge, hoping to make the compressor come on but to no avail…

At this point, I bought a set of A/C manifold gauges to get better measurements and enable more repairs later. According to a couple static pressure readings last month, a week apart, the system seems to be holding pressure but it’s too hard to tell. I pulled the power connector off the compressor and verified by voltmeter that power gets to the compressor any time I turn the bypass switch on when the engine is running.

Therefore I’m left to conclude that the A/C electrical system is okay but I most likely need a new compressor, and of course a new receiver/dryer, but I’m debating on replacing the condenser as well. What are your thoughts on this?

My plan going forward is to spray all A/C lines I can access with soapy water to check for leaks to see what else needs repair or replacing, while I still have pressurized refrigerant in the system. Once I find those, I plan to order the parts and then have the system professionally evacuated so repairs can begin. I’ll get a vacuum pump as a loaner from my local auto parts store and use my manifold gauges to refill the system. Does anyone have any other pointers or things I may have missed here?

Also, since my system originally used R-12, the factory fill sticker calls the refrigerant amount for R-12 (800 grams or so). What would be an equivalent amount of R-134a? I’ve read several places to use 70-80% of the original R-12 amount in R-134a but can anyone back this up?

Thanks so much for your help and reading this!