Related issue that happened the same day as this thread…
https://www.skoolie.net/forums/f49/t...rts-36363.html
Once I got the engine running, the air alarm went off. I let the pressure get up to 90 or so, but the alarm stayed on with the dash light. Waited a few more minutes…still going off, pressure holding steady. Mind you this was day two with the bus so I forgot that the pressure should have been 120, not 90…
Made a calculated risk move and decided to start driving. Brakes worked just fine, recovered pressure after a stop, even heard the air dryer purging and compressor cutting out normally, but the alarm was still going off. Pressure never went below 90 the whole way home, I think the max was 110 but I don’t remember for sure.
When I got home, I did notice that I could hear an air leak when the engine was off, coming from the air dryer; I’m already planning to replace it. I ran the engine the other day but didn’t drive, tested the brakes, pumped them down and revved the engine to build pressure back, didn’t see any issues. So why wouldn’t the air alarm shut off the other day? Did it “know” there was a problem with the air dryer or is it a possible bad sensor?