Hi,
I have a 1987 E-350 cutaway nose on my motorhome with , I believe factory ac. I say this because it doesn’t have a low pressure switch anywhere I can see, including the dryer ( no port). Pretty tight quarters with a 460 shoehorned in there! Anyway, the issue is this was converted to R-134a before I got it and the AC didn’t work, but the compressor came on. I posted the in a different section of this forum and someone was nice enough to direct me to this sub forum. I checked the pressures and they were low so I added r-134 to it. The cooling was lackluster at best, plus the compressor never cycled off, just stayed on all the time! I then evacuated the system and out came 8-9 ounces of refrigerant oil! My guess is this should have 3-4 ounces in total in the system, so a previous owner overfilled that crap out of this! I’m hoping that they used ester oil that was compatible with the original mineral oil.
Fast forward, I added r-134 and now it works a little better but still not great and the compressor stays on when dash switch is on AC, no cycling so I’m going to evacuate it again, change the dryer which I suspect is oil saturated and flush the condenser and evaporator core before trying this again. The poster on this forum that was nice enough to refer me to this sub forum educated me about how some Fords of this vintage, used a clutch cycling thermostat in the hvac housing instead of a low pressure switch on the dryer to cycle the compressor. I never knew that so thanks for the tip👍
Does anyone know what the correct amount of oil is for this system? Also, does anyone have an electrical schematic for this ac system?
thx
Bruce