Onan Generator 7500 Won't Turn Over

[Troy Price]

I am new to the BAC Forum so if I am posting this in the wrong place, just give me a heads up, so I do not keep do this.
This is the problem I am working on, and it is driving me crazy should be an easy fix. I have a 2004 Beaver Monterey, and this is my second year with the coach. I just got it winterize for this winter, and I thought I would double check everything before I put it in the shop for the winter. I found that the generator was just a little low on oil, so I topped it off. After doing that I check the oil level and all looks good. I thought I would start the Gen and have it run for a little and then recheck. I went to use the starter switch on the Gen and found the light on switch did not light up, or when I tried to start the Gen, it did nothing like I had no battery. I checked the battery, and all is good lots of power. I also checked the power leads to the battery in the back of the Gen and had power. I also looked at the switch on the dash to start the Gen, and the little white light that comes on when trying to start the Gen did not light up. I also check fuses in the Gen all is good. Does the Gen have some safety switch to stop it from running if to much oil is in it? But again the oil leave looks good, so I’m just grasping for some ideas on why it just stopped working.
Any thoughts on this?

[Steve Huber Co-Admin]

Troy,
Welcome to the Forum.
Try starting it with the battery boost switch pressed.
Steve

[Troy Price]

Steve,
Thanks for your thought on this, the power boost made no change.

[LaMonte Monnell]

Are you sure your batteries are charged up?

If the battery boost didn't help to start it I would think the batteries are low.

[Troy Price]

On the back of the Gen where the battery leads go, I have my voltmeter and it reads 12.3 volts all the time does not drop when I try to start the Gen.

[Steve Huber Co-Admin]

Troy,
I think there is a fuse and the start relay (K1) located on the generator control board.
Steve

[Keith Moffett]

Hey Troy, welcome to the Beaver family and forum.
I am not sure about your model Beaver if it has the gen on a front slide or it is under the side.  Regardless there should be a start button on the gen set.  Have you tried that?
12.3 volts is low.  Fully charged batteries should be 13.2 to 13.8 V.
Seems like the start button by the driver is just activating a relay that powers the generator starter so perhaps a bad relay?
A good start might be getting the model and serial numbers of your gen set and looking it up on the Onan / Cummins site.
Good luck.

[Joel Ashley]

12.3 is low, but should crank the genset.  Regardless, first get your battery banks topped off.  The fact you didn't get the light on either of the switches implies they aren't getting volts.  The starter solenoid has available cranking voltage, according to your check, but the switches aren't passing power through to it to close the big contacts. 

In the front streetside bay you might check the integrity of the gen's ground connections, the top 5 nuts on the far right buss bar on the back wall of the bay in our '06.  After that I'd remove a switch and/or get at its back and double check that in fact there is no voltage on any wire.  And make sure connectors are secure on them.  If no voltage is present, use an ohmmeter while the switch is exposed to see that it will actually work properly whenever you do get voltage restored.

Beyond that others here will have to guide you as to tracing the hot lead between switch and battery, as I've no experience there;  the clue being that neither switch lights and apparently has no viable voltage input, so there must be battery circuitry common to both that is faulty.  As Steve notes, it could be a relay if not the fuse you checked.

Joel

[Larry Dedrick]

Troy
       There are several 2 or 3 relay in the front of the Gen Set inside the cowling. I'm not saying this is your problem, however on my start issue (starter not engaging at intermittent times) it turned out that the relay for starting was faulty. It was replaced with a Sealed relay and it is recommended to use only a sealed relay. There is a tremendous amount of dust that passes by these relays when the Gen set is running and if they are not the sealed type you could have potential problems. I opened up the old Unsealed relay and couldn't believe the amount of dirt inside of it. Just wanted to pass this on.
     Good Luck.    Larry D.

[Troy Price]

Thanks
I will dig into that this weekend and see if that is giving me the trouble.

[Larry Shelton]

you must have more than 1/4 tank of fuel. With low fuel you will only hear a slight grunt from the fuel pump and starter will not engage.




Larry Shelton
06 Monterey

[Doug Allman]

For someone that is new to club or motor coaching that needing 1/4 tank of fuel is so that you do not run your coach out of fuel with generator then cannot drive to get more fuel. There are a lot of things on the learning curve with a coach that were not in our prior to days to owning a coach.

[Joel Ashley]

Certainly I agree about the fuel level component, but Troy's switches aren't lighting up;  his problem is electrical.

Joel

[Troy Price]

This weekend I decided to jump into this with both feet.  After getting to the starter and getting 12 volts until I try to run the fuel pump or start the voltage goes to zero, wait a minute or two and I see 12 volts again. I was a little confused because at the back of the generator I still had 12 volts. I traced the cables on the starter side and found two power studs on the inside of the housing. Also found the Hot stud and the Ground stud was very loose. I removed and clean connection and reassemble with one change I used Stainless Steel Swivel to Rigid Lock Washer. I did not want to see this problem again.
Thanks everyone for your help, glad to have this fixed.