Mep-831a over voltage

[Lettja]

Hello,

My mep-831 voltage will not adjust from 125 volts i have already replaced the old variable resistor after testing it but the new one has the same problem so i dont know what else it could be and the TM doesn’t cover this fault.

Any help would be greatly appreciated.

 

[kloppk]

First I'd suggest testing to be sure there is continuity between the AC adjust potentiometer terminals and the inverter.
P17 is the long white-ish plug near the top of the engine side of the inverter.
P7/J7 is the large round circular connector pair from the engine bay into the control cube.
Here is the schematic of potentiometer wiring to the inverter.

 

[Lettja]

I got continuity through both points although there is a broken pin in J7-17 could that be the problem or another issue? Like should i replace the harness or run a bypass?

 

[Guyfang]

Where are you going to get not just the harness, but also the plug side. The MEL for that set is so low, you can not order the parts.