Onan 5.5kw GenSet wont turn over

[Rich1]

About two months ago I put my RV in storage. The generator started up fine at that time. A few weeks ago I went to start it up and my chassis battery was dead. I was able to easily jump start my RV and I let it run for a bit. When I attempted to start the generator it would only slowly turn over but not start, I figured it was due to the dead battery. Today I went back to start my RV and generator up and again a dead chassis battery. I was again able to easlily jump start the RV and this time took it for a drive and then let it run for a bit. When I went to start the generator with the remote switch and at the generator all I would get is a fast ticking sound. Any ideas or advice please, I am trying to sell it and I am a little concerned.

Thanks,

Rich

[Stan.Birch]

Your only reasonable option is to get a voltmeter, and learn how to use it.

It's really not all that difficult, notwithstanding, it can be a lot of fun learning new skills essential to managing an RV.

[Rich1]

A voltmeter? Okay I will look into that, but does that mean you think this is still stemming from my battery issue?

[clyon51]

Are you 100% sure your genny is started by the chassis battery? Most are not, which creates a whole new set of diagnostics.

[Rich1]

Yes I am, I pulled out the manuals and it did specify the chassis battery, I had the same question too. My RV is a 1999 Mountain High Coachworks Pinnacle 3790.

[LKANER]

Are you sure your generator starts off of the chassis and not the house ? Are the house batteries at full charge ? When my chassis battery was draining I found it was the radio and by changing the radio power switch from engine to coach the drain stopped. Because i do not have a chassis battery kill switch I installed a Trik-L-start which keeps the chassis battery charged via the house batteries which are maintained by the solar panel.

[clyon51]

Originally Posted by Rich1

Yes I am, I pulled out the manuals and it did specify the chassis battery, I had the same question too. My RV is a 1999 Mountain High Coachworks Pinnacle 3790.

Not familiar with your coach, but will proceed on the fact that the chassis batt starts the genny.

Your chassis batt is probably shot, so replace. However, if engine was running when trying to start genny, the alternator should have been producing enough to crank it.... maybe.

So check batt posts to be sure the cable to the genny is clean and has a good connection. Most gennys do not have a ground cable going back to the batt. They have a grounding cable from the genny frame that connects to the chassis frame near the genny location.

Since yours is a '99, it's a good bet the ground at the frame is corroded and does not have a good connection. So check and clean that as well as the ground at the genny. Then make sure the POS cable at the genny is clean and tight.

[Rich1]

Okay I just went back and re-read through my Onan op manual and it says " These gensets have a 12 volt, direct current starting and control system. Usually, the 12 volt battery used for vehicle lighting and other 12 volt DC vehicle loads is used for genset cranking and starting up." I know I read somewhere that it starts from the chassis battery, I thought. This does sound more like the coach batteries. which were also pretty low as well. Now if they are the culprit would that also explain my slides not moving either? Because I thought the generator had to be on for those to work.

[clyon51]

Originally Posted by Rich1

Okay I just went back and re-read through my Onan op manual and it says " These gensets have a 12 volt, direct current starting and control system. Usually, the 12 volt battery used for vehicle lighting and other 12 volt DC vehicle loads is used for genset cranking and starting up." I know I read somewhere that it starts from the chassis battery, I thought. This does sound more like the coach batteries. which were also pretty low as well. Now if they are the culprit would that also explain my slides not moving either? Because I thought the generator had to be on for those to work.

The onan manual could not possibly know how a particular RV mfgr would wire their product. That said, most RV mfgrs do use the coach batts for the genny.

Certainly the coach batts operate the slide(s). So if they will not ooerate, it is not surprising the genny will not crank. It would seem you have a coach batt problem. Which can be many things.

[Rich1]

I really appreciate you taking the time to help me. I am pretty new to this, my wife and I inherited this RV so I am learning as I go. If you wouldn't mind me asking what types issues might I be facing with it being the coach batteries.

[Stan.Birch]

Originally Posted by Rich1

Okay I just went back and re-read through my Onan op manual and it says " These gensets have a 12 volt, direct current starting and control system. Usually, the 12 volt battery used for vehicle lighting and other 12 volt DC vehicle loads is used for genset cranking and starting up."

That's not a normal arrangement. The gen usually starts from the house batteries; and then, if the house batteries inadvertently get drained, the most common procedure, is to start the RV engine, and then enagage the AUX battery switch to bridge the chassis battery with the house batteries, providing the necessary power to start the gen.

If you have a really old RV, the battery isolation solenoid might be screwed, so as a last resort, clip a battery booster cable between the red wire on the chassis battery to the red wire on the house battery, and give it another shot!

[clyon51]

Originally Posted by Rich1

I really appreciate you taking the time to help me. I am pretty new to this, my wife and I inherited this RV so I am learning as I go. If you wouldn't mind me asking what types issues might I be facing with it being the coach batteries.

A whole bunch of things. If you leave the coach set without being plugged in, that will allow the coach batts to drain and go dead. If this coach is new to you, they could be bad to start with. The charger could could be bad if you have left it plugged in. There is a whole range of possibles. If you can give more specifics as you known them, we can help more. Age of coach, brand, model, age of batteries, what kind of charger, ect. Just start with what you kbow and we can go from there.

[Rich1]

Yes it could be possible that they are bad. The RV has not been plugged in for a good two months, the only storage facility that had an open slot big enough does not have power yet due to it being fairly new. It is a 1999 Mountain High Coachworks Pinnacle M-3790 with a Ford V-10 gasoline engine. The gen is an Onan Marquis Gas/BGM 5500 watt. I am not sure what you mean by the charger so if you could help me with that. Besides the charger is there any other info that could help?

[Rich1]

Oh and the age of the batteries I am not certain of, but I would guess 3-4 years old. I will have to look at the batteries to confirm.