Voltage Regulator Replacement

Cummins Onan RV QG 4000

Where is the voltage regulator?

Can it be tested/replaced without pulling the generator out a PC 2551?

Cummins Onan RV QG 4000

Where is the voltage regulator?

Can it be tested/replaced without pulling the generator out a PC 2551?

Here’s the Onan service manual:
https://www.rvwithtito.com/download/Onan4000MaintenanceManual.pdf

It appears to be a relatively easy task.

Location- see fig. 6-2 in sect. 6-3

Test procedure - see sect. 9-12

Before getting into that try using the carburetor altitude adjustment knob to lower the engine rpm’s.

UPDATE:

It's the EMS not the generator voltage regulator. If I take the EMS out of the picture the generator voltage stays around 123v. I I enable the EMS the generator voltage stays at 123 but the EMS will report the same for maybe 15 seconds and then jump to 135 and then trips out disconnecting the power. Turning off the EMS then routes power to the distribution panel again.

Another thing to note: my last two trips I made I noticed the EMS reporting 135v and often tripping out. I was complaining in my head that it was the RV campgrounds I was staying at. Now I know that wasn't the case.

The original electrical converter on our PC2100, a Magnatex 6332, was based on an analog design.  As it accumulates time and use, the unit is known for over-charging the RV's 12v battery.  I replaced this with a Progressive Dynamics PD4635 unit.  Also replaced the stock 12v fuse block with an updated one which, if a fuse is tripped, will display an red LED light Located directly below the blown fuse. The upgraded converter maintains a better battery charging cycle, as well as preventing an over-charge.  Along with added protection for 12v electrical devices operating in the RV.  The swap took several hours, most of it being the time it took to wire a jumper onto the positive cable.  The original one being too short to reach the contact on the new converter.