In chasing the cause of my A/C twice blowing out the pressure relief valve on the dryer, I ended up discovering that my system had too much oil in it. Also discovered a damaged fitting on the condenser so that got replaced, replaced the expansion valve and pressure switch because they're cheap and I had the system opened up already, and replaced all the O-rings. As I was servicing it up yesterday I saw the high side pressure continue to climb up past 300 PSI before I shut off the A/C and let it equalize back down and cool off. When I switched it on again to watch the gauges I noticed that my radiator fan wasn't coming on and cooling the condenser (which will cause excessive head pressure in the system that I witnessed earlier). So I had to dig around in the wiring behind my dash for the fan's cutoff switch, indicator light and the A/C control circuit (which ramps up the fan when the A/C compressor is engaged). Found the primary fuse blown so I traced all my wires (ugh) and found the ignition switched lead for the fan cutoff which I had inadvertently pinched and shorted to the ground I think when I had changed out my dash pad. Along the way I found some damage to my gauge wiring harness and one of its connectors that I'm fixing right now, and will be adding spiral and split loom to the loose wires behind my dash in an effort to prevent future pinching of wires (got lazy before and paid for it, though fortunately was smart enough to fuse my IGN lead during the initial install). Fortunately the way I wired my kill switch and integrated it with the indicator light, disconnecting it from the fan controller still allowed the fan to operate and maintain the engine temperature. Dunno what gave me the foresight to wire it like that, but glad I did. So I spent yesterday evening diving into all my wiring with my multimeter and making sure everything is now okay. Will continue on when everything is back together and the wiring is all repaired and cleaned up. Busy busy last couple days on my 62.
So as it turns out, even though my A/C did have more oil in it than it should have, that was likely not the cause of the over pressurization that blew out two dryers like I had initially suspected. Looks to be the cause was the shorted IGN lead causing the fan to not ramp up with the A/C compressor being on, which led to insufficient airflow over the condenser.
The adventure continues!
So as it turns out, even though my A/C did have more oil in it than it should have, that was likely not the cause of the over pressurization that blew out two dryers like I had initially suspected. Looks to be the cause was the shorted IGN lead causing the fan to not ramp up with the A/C compressor being on, which led to insufficient airflow over the condenser.
The adventure continues!
