My AC compressor was not starting. Thanks to the posts in this topic, I was able to get air conditioning working again
I put 2 cans of R12a in it, because there was residual pressure in the system, I figured because of that I did not need vacuuming it down. It did nothing. There is no label for the fuses/relay bank under the hood, and none in the user'* manual, so I looked on the forums to find where it is (besides the horn relay). I had replaced the horn relay before, so I had the older relay, which I took apart and plugged it into the relay socket. Depressing the relay caused the compressor to start, so there was no problem with the compressor. I know, I could have used a jumper wire or a paperclip, but I did not want to have an accidental short.
I bought a gauge and it showed 60 PSI. I thought it was too high, since the instructions said it needs to be filled to about 30-38 PSI. However, this is the value while the compressor is running
, so I just had to get the compressor running.
Yesterday, I found out about the diagnostic mode, so I ran it and hey the compressor started when I fiddled with the fan switch, but when I drove it around it stopped working. However, I figured it was too cold for it to work, it was 15C. I have the climate controlled version of the AC controls. I got code 00, but with a whole lot of other numbers depending on the setting of the fan switch.
So today, being warmer, external temperature 24C, I bought yet another can of R12a and with the gauge on, the compressor did not run either, but now, I got a code 66 and even a 166. I ran the compressor by the same method I did last night. I realised the cycling pressure switch opens at slightly below 30 PSI. As it cycled, I added more, until I think I added too much. It stopped cycling. It was hard to tell if the receiver was sweaty, but the return tube (the one with the low pressure service fitting) was quite wet. There was relatively cold air coming out of the vents.
Then I recalled that the instructions say to run it at 2000 rpm, so I did that and the compressor cut off when the pressure dropped. So I took it for a drive and it was blowing relatively cold air, colder than usual anyway, I did not use a thermometer to find out.
So there you go, that was cool. Sorry, could not resist
I still have some questions though. The Haynes manual show a refrigerant pressure switch and an overpressure cutout switch, in series with the pressure cycling switch. I cannot find these two other switches. Where are these switches located?
Obviously, there is a low pressure sensing switch, otherwise how does it know code 66... and I suspect it is near the evaporator, but since I did not remove all the dash to see, I am not sure.
The second question is where is a list of all the codes that the climate control spits out when it is diagnostics mode?