MEP-803A3 oil pressure gauge help

[aauthement]

I have a MEP-803A3 with a Beede 945330.

I am having the following issue with it.
When the generator is off the needle stays where it was when it was running
when I turn it off (see the picture of the face). When I start it, it goes to zero then stays at the highest pressure. I am thinking the wiring maybe mis wired or defective gauge.

I am trying to understand what the terminals are on the back of the gauge.
L = light power
G= ground
S = Sender
I = Power 24v
O = ?????

I have the following wires connected on the gauge.
100AN20 ground
100AP20 ?
130B20 from sending unit
137J20 not sure
M7-1 (137J) not sure

Can someone tell me which wires go where?

I have searched everywhere trying to find what these wires are and what they connect to.

The picture of the face of the gauge is disconnected from the generator.

Any help would get greatly appreciated.

 

[Light in the Dark]

That's how the gauge works, sounds like no issue. It shows pressure at end of last run, and zeros out upon new startup procedure.

 

[Ray70]

Your wiring description is correct. Nothing goes on the O terminal except the mounting strap nuts.
Make sure your mounting strap has plastic inserts in the holes to prevent shorting the O and Ground studs together.
As LITD stated, the gage operation sounds correct except for 1 thing. When you say it "goes to zero than stays at the highest pressure" what exactly do you mean? It should go to zero when power is turned on, then go to the current pressure when the motor is started. Are you saying it pegs itself all the way up??

 

[Ray70]

Regarding the actual wire numbers, you can look at the schematic on the side door and find your oil pressure gage, the schematic will show you what wire goes where. Note: you will have 2 wires on the ground stud and probably 2 on the "I" terminal as well because the gages are all daisy chained together for power and ground and I believe the oil gage in in the middle of that chain.

 

[Guyfang]

M7