Makita compressor. What am I missing

2 years 10 months ago #3541 by mullenj
Makita compressor. What am I missing was created by mullenj
I picked up a free Makita MAC5200 compressor off of someone because it wasn't working. He said he'd had a crack at it and he thought it was the pressure switch. Compressor is in like-new condition, if the previous owner used it at all its not obvious. He probably could have gotten a warranty claim out of it.
Issue: Turns on, runs for ≈5 seconds, and turns off. 
My process:
First thing I did was check if it was an issue with the pressure switch, I opened the cover on the switch box and put a multimeter on the motor side of the switch. When the motor shut off there was still power running through the switch. No problem there.
It was at this point that I found out it was shutting off because the thermal overload protector was being thrown. This could be from a number of things but the easiest to test was the centrifugal switch. I threw a multimeter on that in continuity mode and started the motor, once the motor got up to speed, continuity was lost. This, I believe, is the proper operation of the switch, cutting power to the start capacitor once it is no longer needed. 
Finally, I tried replacing both the start and run capacitors with brand new ones.
The issue persisted. 
I thought maybe it was an issue with the thermal overload protector itself but was kind of over ordering parts for something that seemed hopeless so, in a hail marry attempt, I bypassed it and ran the compressor without it. I thought I had it solved when it ran for longer than 5 seconds but then when I started to let the smoke out I realized I was wrong. 

If anyone has any other ideas of things to try I'd love to hear them. The only thing I can think at this point is that there is a short in the coil somewhere or it was wired wrong from factory, if anyone has a wiring diagram for this thing that would be huge. Is it normal that the start and run capacitors are linked directly together? Seems strange to me.

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