MEP806a issue

[SandBar]

Low hour unit, starts and runs great with all new filters and fluids.

However, fuel level and oil pressure arent responding (could just be senders). The bigger issue is volts are only coming up to about 14 to 18 on the gauge, no frequency registering. Rotating the voltage knob does not affect volts.

Looking behind the panel all "looks" intact, aside from finding a few fasteners and a big spare fuse when I first got it.

Someone had also disengaged the dc re-settable fuse behind the panel as well. The oil pressure gauge doesn't move, being an electric sender on that I am less worried that it is an engine issue but rather an electrical gremlin. It seems hard to believe a handful of modules are bad resulting in this issue. The two big units at the back, I think are the voltage regulator and the black box that runs everything could they be the issue?

 

[SandBar]

Adding some photos to aid the triage.

 

[SandBar]

Reading this made me question, could the fact the oil pressure gauge is not working be causing it not to flash the field and come up to voltage?

" Holding the toggle for about 3-5 seconds in the start position after the oil pressure comes up and both the voltage and freq. come up to where they are suppose to be. Did not realize this was required upon start up. Happened on it by sheer accident. "

 

[SandBar]

Comparing photos of other mep806a, most of them have voltage regulators that say Libby across them (generator is a Libby build according to the tag) and the installed VR says TRC. Could this be a case of someone at the base replacing the VR with the wrong one? I see it has the quad fuse mod which is good.

 

[Guyfang]

The oil pressure has nothing to do with excitation. Are you sure you are holding the S1 up long enough?

 

[Guyfang]

Look at the attached info. If your set is made by Libby, that doesn't mean only a Libby A1 will work. It could be a Libby made gen set, that has all the listed parts changed over to TRC.

SO,

You need to look at all four of the listed parts, and determine that ALL four parts are from the SAME manufacturer. You can NOT mix and match.

 

[SandBar]

I tried holding it in the start position for up to 15 seconds with no change. Ok let me check all those parts. I understand it is an lower speed generator, but I can't tell what the rpm is by ear, could it be running a few hundred rpm slow and doing this?

 

[SandBar]

The oil pressure has nothing to do with excitation. Are you sure you are holding the S1 up long enough?

Just to clarify, this means turning switch to start and holding it there for a few seconds correct?

 

[Guyfang]

Correct. And you also do not have anything on the 120 volt outlet?

 

[SandBar]

I plugged in a light and got nothing. Can check it with a meter.

 

[SandBar]

Ok, checked and all 4 components are TRC.

Quad fuse is intact.

When running I see about half a volt at the lugs. Oddly the panel says about 30 volts but I can't get that reading anywhere.

What should I check next?

 

[kloppk]

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