Diesel Onan 8k Wont Start -2007 Meridian 36g

[Rjmossyoak]

Hello, we are at the Midwest Nationals this weekend. We are having to run off of house batteries and generator because no shore power here. We ran generator for awhile yesterday morning and when we got back it wouldn't start. It would go through the clicks are heating glow plugs but starter would never engage. We tried everything and could never get no results. We plugged into a friend's generator last night and everything is charged and still the same thing. House batteries are only a year old and we also had a new one that we stuck in to try and nothing. Any ideas much appreciated.

[Morich]

First quickie to see if low battery is a problem? Try starting the Rv engine as that connects the chassis battery and alternator to coach and assures good voltage.
Second thought would be to check the battery cables from the coach to the solenoid on the generator. The click often means you are getting enough power to that solenoid to pull the contacts (click?) but not enough to turn the engine to start cranking.
Depending on what year and if the cables have been changed there may be a "code" for tape on the cables for ID?

If you tell us which RV, there may be drawings to show the route and where connections might be on that cable.

[creativepart]

Like any engine there are a few "simple" things. But it sounds like the battery is good enough to do everything but engage the starter.

That points to the starter solenoid. It could be bad or just "stuck." Do you have access to it? Onan likes to tuck things away. I've always heard stories of people rapping the solenoid with a metal wrench and temporarily fixing the issue. But I've never had to do so.

Most important is the heavy duty wiring connecting the batteries to the solenoid. And making sure that they are totally sound and making a good connection.

After that, it may be time for an Onan Tech to take a look.

[Morich]

The solenoid operation is much the same as we find on cars but possibly smaller number of things between the key and the solenoid to go wrong.
The idea is that we turn the switch/ key, etc. and that sends power to the solenoid coil. that power then goes through a coil and makes the contacts move to close.
If the noise/click you hear is from the solenoid on the generator, it indicates power is reaching it to make it move. If that power or voltage is high enough, the power has to get through the contacts to reach the starter motor and crank.
There are several things that can make the click, close the contacts but still not crank.

One is the battery is just strong enough to move the contacts but not turn the engine.
Having the RV engine running should solve that problem.
A second problem can be the contacts close when you hear the click but they may be corroded and burned to a point that doesn't allow enough power to pass to crank.

Once you have tried giving it more power with the engine running and it still doesn't crank, there is a fairly simple test for bad contacts.
There are two big contacts on the solenoid. If you short those two big contacts together and the engine turned, it leans toward the contacts inside being bad and you likely need a new solenoid.