Onan 5500 generator won't start.

[roundtrack]

I have a 2018 Winnebago Vista 35F which I keep under a shelter and hooked up to a 50 amp service when not on the road. My generator just clicks and won't start with the 50 amp service turned off. If I turn on the 50 amp service, the generator starts right up. I checked all the batteries and they are fully charged. Any ideas to get this squared away sure would be appreciated.

[Winterbagoal]

Assuming the generator uses battery power from the coach batteries to start, and there's no power to the gen, with the 50A power off, check the salesman switch (coach battery enable/disable) first. Your system might require it to be enabled for starting power to get to the generator.
If that is not the problem, then turn off the 50A shore power, then recheck the coach batteries SoC after turning on a few 12VDC lights or the water pump for a few minutes, to remove surface charge from them. It's probably low/bad coach battteries.

[roundtrack]

Thank you for your help.

[BitSlayer]

I agree with the above. I had the same problem. When I tried to start the generator, it would simply click and not turn over. I even opened the compartment and tried to start it locally with the same result. After some research, I found that having the coach power switched off will cause this issue. Make sure your coach is powered first, then look at disconnecting the 50A service. My generator will start even with the engine running and the 50A service connected.

[Hicks3456]

Shouldn't the generator start anytime? I can see different reasons I might want to start it in any configuration for multiple reasons.

[BitSlayer]

Originally Posted by Hicks3456

Shouldn't the generator start anytime? I can see different reasons I might want to start it in any configuration for multiple reasons.

That is what I thought as well. Unfortunately, if the cabin power switch is not on, the generator will not start. At least that is how it is configured on my Vista.

[Hicks3456]

I guess that makes sense - it uses the battery power to start. If the batteries are dead I guess you are out of luck for power. I also have a Vista with the 5500.

[powercat_ras]

The starting cable to the generator comes from an ANL fuse attached to the load side of the coach battery disconnect solenoid located in the chassis electrical box. If the coach batteries are down and can't crank the generator, then start the coach and give the Battery Isolation Manager (BIM) a couple of seconds to bridge the alternator and chassis batteries to the coach batteries circuit. Normally will do the trick.

[Morich]

If we think back to the older days when cars had solenoids on the starter, we can see what is happening as it is a pretty "standard" result. I would assume the click being heard is the generator starter solenoid engaging but when it does, the engine doesn't turn over as the battery supply is too low to get the heavy current flow needed. When we have the RV plugged in, that power is there, just not coming from the batteries.
As mentioned, we can often get that power to the generator starter if we are plugged in or if we start the RV engine which also provides charge to the batteries. Either way works but the final solution is to find why the batteries don't have enough charge, either they are not getting the charge or more likely, they are not in good shape to take and hold that charge.

[dickb46]

Long shot but maybe the leads from the battery to the generator starter have a bad connection. That was my problem with my jacks not working unless I had the engine running.