Onan Generator Problem

[steve crews]

I have a Leisure QG 3600 LP Onan generator.  I was changing the air filter which is difficult to get out.  I detched the battery cable and to gain easier access.  I then almost had to pry the air filter out after removing the case and wing nuts.

In so doing, I touched the battery cable to the metal housing, causing a short/arc.  Now I don't have any juice to start the generator.  Checked fuses, breakers in numerous places. House batteries that power generator starter are fine. Any suggestions?

[Wrknrvr]

  I would suggest testing the battery terminal end you took off and shorted out with a volt meter. If there is no voltage on the terminal end, then check the cable itself where it goes into the cable end.

   If there is no power there, then physically trace that wire towards the batteries. Check voltage at any connection until you get to the batteries. Also check the cable connector on the end and the cable itself. You may find a bad connection that just happened to quit with your sparks.

    What kind of rv is this in.

  I had a bad fuse on the supply wire for a leveling Jack system last summer. Finally called the factory. That fuse was on the rear of the electrical distribution panel center. Possible 3 hrs time to remove solar control and wiring. And disconnect all 12 vdc things to get to that fuse. And reassemble it.

    Talked to factory and we both said to mount a new fuse block on the face of the 12vdc panel, and make it look like a factory install.

   Hope this helps,    Vern

Edited March 16, 2023 by Wrknrvr

[Kirk W]

The Onan website has operator, installation, and parts manuals available if you need them. The installation manual (here) has some information on the starting power connections beginning on page 8-4. I agree with Vern that the place to start is by checking for proper voltage on the cable that was lifted. There is a good chance that the cable has a fusible link, or fuse in it or between it and the RV battery it connects to and that it was opened by the power surge when it shorted. 

Keep us posted on what you find and we will try to help. 

[steve crews]

It's a leisure travel van 2020 wonder.  No good way to trace it back unless I was a mouse. Fuse is good at house batteries that supply the generator to start it. Positive cable that I shorted is now dead. I checked fuses and breaker panel in rv, all in tact.  Thanks

 

 

[Kirk W]

3 minutes ago, steve crews said:

Positive cable that I shorted is now dead. I checked fuses and breaker panel in rv, all in tact.

Most likely there is a fusible link that is open. Check that battery cable with your ohm meter. It will probably measure as open. If so you will need to either find that fusible link or replace the battery cable. 

[steve crews]

Ok, I'll pursue those directions ... in contact with the manufacturer in Manitoba, Canada, but playing phone tag to get a service person's advise.  Thanks for the input.  Steve crews

[Rotorhead]

Hello,

I tried to start my generator today. No luck. It just made a solid click sound. It’s a Onan RV OG 4000 by Cummins. 
I am assuming maybe the start solenoid? I haven’t started it for six months or so. Ground looks a little corroded so I’ll clean that when I get a chance. 
Any other things I should check?

Chuck

[sandsys]

Generators prefer to be run. The general rule is once a month for 30 minutes under load. We liked to run ours with the A/C on while moving from one site to another. That way it didn't bother any neighbors.

Linda

[Rotorhead]

22 minutes ago, sandsys said:

Generators prefer to be run. The general rule is once a month for 30 minutes under load. We liked to run ours with the A/C on while moving from one site to another. That way it didn't bother any neighbors.

Linda

Thanks. I will have to make it a priority once I get it running again. 
Chuck

[bobsallyh]

Did you check the start voltage coming to the Onan. Had the same issue last Thursday. I run a separate start battery for genny. Hit the start and a solid click. Checked the battery voltage, 11.8. Of course when hitting the start button it dropped dramatically. Replaced the battery and good to go. The start battery was 9.5 years old.

[Rotorhead]

49 minutes ago, bobsallyh said:

Did you check the start voltage coming to the Onan. Had the same issue last Thursday. I run a separate start battery for genny. Hit the start and a solid click. Checked the battery voltage, 11.8. Of course when hitting the start button it dropped dramatically. Replaced the battery and good to go. The start battery was 9.5 years old.

I haven’t done anything yet. I will check the volts tomorrow if it’s not raining. Thanks for the info. Hopefully it’s that easy. 
once it’s going again I will be starting it monthly. 

[Rotorhead]

1 hour ago, bobsallyh said:

Did you check the start voltage coming to the Onan. Had the same issue last Thursday. I run a separate start battery for genny. Hit the start and a solid click. Checked the battery voltage, 11.8. Of course when hitting the start button it dropped dramatically. Replaced the battery and good to go. The start battery was 9.5 years old.

Ok. I checked the volts in between rain showers. It is 13.5 at the solenoid and only drops to 13.4 when you press the start button. 
bad solenoid?

[Rotorhead]

I pulled my house batteries out last night to put them on the charger. I checked them and they were both 13.13/14. They are original from 2017. I was thinking maybe just replace them since they are pushing 7 years old. 

Is it possible to have a good reading but have a bad cell? 

I am replacing the solenoid next week when I am off and have some time. 

[bobsallyh]

Rotorhead, I wouldn't get too excited about the solenoid yet. My next move would be to put the battery charger directly to genny and try to start it. If your charger has a "start" function, use it. I wish that I could be more specific, but I have trouble using a keyboard to troubleshoot. Hands on, a piece of cake.

Edited June 3, 2023 by bobsallyh

[Case20hp]

Yes you can have a bad cell and get a good voltage reading with no load. If you load test them it will usually show if they are still good. I have had batteries last 10 years and others not make it a year. 

[Rotorhead]

Ok so I found my problem. The bolt for the ground was rusted really bad and the bolt head was hanging. Plus the copper bonding strap was corroded so bad it fell apart.

once I got it all disassembled and found a couple new bolts to use I reassembled it. I had to make a new ground wire. I just used a piece of some 14ga wire from when I finished the basement. 
When I was done it started right up.

So, check those grounds. They may be corroding. 
Chuck

[Rotorhead]

On 6/3/2023 at 7:03 PM, bobsallyh said:

Rotorhead, I wouldn't get too excited about the solenoid yet. My next move would be to put the battery charger directly to genny and try to start it. If your charger has a "start" function, use it. I wish that I could be more specific, but I have trouble using a keyboard to troubleshoot. Hands on, a piece of cake.

Thanks. Sorry I just saw this. Today was the first day in a month I had to look at it. It was a bad ground. More like totally shot. Corrosion.

[gypsydan]

What a joy it is to Rv. I have been wanting to put new plugs and yes filter on my own and 4000 and Sew have been buying the parts on Amazon, and when the plug comes in this Friday, I was going to install them.

What a joy it is to RV. I have been wanting to put new plugs and yes filter on my own and 4000 and so I have been buying the parts on Amazon, and when the plug comes in this Friday, I was going to install them.

Then in reading this post, I realized I had not started my generator for a couple of months, so I decided I better start it just to get it warmed up and run for 30 minutes once a month. Turn the engine on, since the generator wouldn’t start right away, and then started the generator. After about 10 minutes, the generator choked up like it was running out of gas and stopped. Now it won’t start. So Friday or Saturday after I’ve gotten my plugs and gas filter I will install them and see if it will start. I also will check the ground wire, as my Thor class C was assembled in 2009.

again, it is a joy reading this forum. But please, don’t let me read anything regarding engine problems.

Edited July 5, 2023 by gypsydan
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