Compressor won't turn off - PCM?

[GeeTwo]

I agree - check for swarf (metal shavings) or another source of a short across the pressure switch terminals. If you can't find anything, replace the PCM, preferably working with the vendor or CTRE.

[ratdude747]

Another thing to check: make sure the pressure switch isn't shorted out; with the compressor running, unplug the switch. If the compressor keeps running, it's a PCM issue (or swarf intrusion as some have mentioned). If not, the switch or its wiring is shorting out.

[Minerbotics4827]

We have unplugged and replugged everything in three times, checking for shorts every time. We didn't find any metal shavings, and even took the PCM apart trying to find any. Even if we unplug the pressure switch while the compressor is running, the compressor stays on. We are ordering a new PCM to test tonight. Until then, we have the pressure switch plugged in as a digital input and are controlling the compressor through code in teleop while we test.

[GeeTwo]

Originally Posted by Minerbotics4827

Until then, we have the pressure switch plugged in as a digital input and are controlling the compressor through code in teleop while we test.

Don't forget that for competition you need to either switch back to a PCM or put the compressor on a spike (R88 C and D).

[ratdude747]

Originally Posted by Minerbotics4827

We have unplugged and replugged everything in three times, checking for shorts every time. We didn't find any metal shavings, and even took the PCM apart trying to find any. Even if we unplug the pressure switch while the compressor is running, the compressor stays on. We are ordering a new PCM to test tonight. Until then, we have the pressure switch plugged in as a digital input and are controlling the compressor through code in teleop while we test.

Yeah, I'd RMA that PCM. That's clearly a PCM issue.