5BGE Onan Generator issue. Yup, I searched :)

[dsmithwc04]

Alright, I've got a 4.8k onan 5BGEFA26100P in a 2000 Winnebago Adventurer.

Please read what I've tried already prior to posting, thanks!

My issue appears to be a common and easy problem to diagnose, but I'm stumped after talking to a few folks who really know their stuff.

The generator will immediately shut down after trying to start it. Disconnecting the RV allows the generator to run as long as the start button is depressed but once you stop holding it down the generator will again shut down.

The stator showed 2.8 ohms on pin 11 and 12. This is within spec.

The rotor showed 50-60 ohms on pin 9 and 10 so I cleaned the slip rings with 1000 grit sandpaper and got readings between 21-31 ohms while rotating the rotor by hand with an allen wrench. This is within spec.

I grounded the oil pressure switch lead to make sure it wasn't dead.

I checked the fuel level in RV which was about 1/3 tank. I've also tried to start when it was over 1/2 tank.

I replaced both the VR and the control board through flight systems.

I believe the fuel pump, ignition, etc on the genny is good since it will run great with the start button held down and the VR disconnected.

The oil level is good as well. I'm really stumped on this one.

[dsmithwc04]

TEXAS wrote:
If it is not producing voltage it will not run.

Correct. I'm trying to figure out why it isn't producing voltage.

[dsmithwc04]

j-d wrote:
Your first post doesn't state the problem. I take it from your reply above, that it starts and runs as long as you hold START but quits.
Do you have an ONAN Service Manual for this genset?

FYI, there's an outfit with the unlikely name "Flight Systems" that has interesting info about ONAN gensets.

Also, interesting hits if you gOOgle "onan bge service manual"

I appreciate your post but you didn't read my original post thoroughly.

I stated that the generator would immediately shut down after trying to start it.

I also stated that I bought a new VR and control board from flight systems so I am aware of the company. They are drawing blanks as after several technical service calls.

I went through the steps I have so far by going through the troubleshooting in the manual. I think I am overlooking something hence I've come to this forum to see if anybody else has had the same experience and perhaps made the same mistake that I might have made.

[TEXAS]

If it is not producing voltage it will not run.

[marcsbigfoot20b]

I just had the exact same problem on my 2500 LP but it would run for a little then stop producing AC power then immediately stop the engine. Was the voltage reg. Did you clean the slip ring before or after you replaced the reg?

[j-d]

Your first post doesn't state the problem. I take it from your reply above, that it starts and runs as long as you hold START but quits.
Do you have an ONAN Service Manual for this genset?

FYI, there's an outfit with the unlikely name "Flight Systems" that has interesting info about ONAN gensets.

Also, interesting hits if you gOOgle "onan bge service manual"

[MEXICOWANDERER]

Check for unintentional neutral / generator-frame conduction.

[dsmithwc04]

Air filter is removed currently to access brushes.

Generator is shutting down because it is not generating power. I believe an auto shutdown condition is occurring because of no power.

[doxiemom11]

Clogged air filter

[Chris_Bryant]

Is it generating power while the button is held down? Might give a clue as to where to look.

[dsmithwc04]

Thanks for the tip. I tried disconnecting the oil pressure switch and starting the genny up but it still dies immediately.

[darsben1]

K Charles wrote:
Unhook the wire to the low oil switch.

My first thought also
Some need to be open to allow running some need to be closed. There is a chart somewhere that tells which but I cannot find it right now

[K_Charles]

Unhook the wire to the low oil switch.