hitachi air compressor wont start at all (pressure switch)

by chido chido
(Vista, California)

Hi i have a hitachi air compressor it wouldn't start one day and i realize there was something wrong with the power cord.

i replaced it and it worked fine for a day the next time it started up again and seconds later it shut off. i empty the tanks and did all the routine check. my last resource was to by pass the pressure switch, and it worked, so i want to know if there is any way to adjust the switch or what can i do before i decide to replace the switch. i looked at the inside of the switch and looks clean there's no burned marks or damaged indicating a short or signs of overheating wires.

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Bill says...

If you bypass the switch with power and the compressor runs properly (except shutting off, of course) and you re-wire through the switch and the compressor won't run, then you have completed a fine diagnostic. It's the pressure switch!

You can tamper with trying to fix them, but my experience suggests that it's a lot less time and hassle to take the switch to the compressor store, and find one to match.

Make sure the new one has close to the same cut in and cut out pressure levels, and that the new switch will interface with your unloader valve properly, once it's installed.

Cheers,

Bill