99 Endeavor Cummins DP Won't Crank

[BandM]

Had a nice new years trip, but now the coach will not crank. Turn the key wait for the alarms and lights to indicate ok to start, turn the key to start and nothing happens.
There are several small circut breakers in the battery bay which I have not checked yet and a fuse box on the front firewall with unmarked relays in a panel.
Does anyone know if this has a circut breaker or start relay ? We replaces the magnetic cummins relay last summer

[Mike Canter]

Normally there is no fuse or ckt breaker inline from the ignition switch to the starter solenoid. It is normally a direct wire and you have power to the switch according to what you have said. There are several possibilities here that can cause this problem. A bad ignition switch, low battery voltage, dirty or loose battery cables, bad starter solenoid or a bad starter. To help try and pinpoint the problem I have to ask a few questions.
1. When you try and start it do you hear any clicking from the starter solenoid?
2. Have you tried to start it while pressing and holding the Battery Boost switch on the dash?
3. If the headlights are on then what do they do when you try and start it? Do they stay bright, go dim, or turn off.
4. The same question on your voltage gauge on the dash. Where is that reading with the switch just on so the dash light are on and what does it read when you try and start it?

[Wizard]

Same thing happened to me a couple of weeks back, found that I had the transmission in reverse. Moved it to neutral and alls well.

[BandM]

Mike I will check Sat and post a bit more. It looks like a battery problem as tonight when I checked the dash gauge shows at the low end of the normal scale. When running it was showing 14 volts. But pressing on the aux start switch did not add extra power so not sure what is the issue there.
Sat I will check the battery connections etc.; see if there is any fuse on the aux connection. I am not sure but I think the solenoid in the battery compartment is part of this system.
I assume the chassis batteries are not charged by the normal 110 system as it has been plugged in 24 hr. and show the low voltage.
But if the batteries are bad could be a moot point
Thanks for your responce

[Mike Canter]

Normally on a voltage gauge that is used there is a large spread between 12volts and 14 volts because that is the way they are designed. If the voltage was still in the green normal area but on the left end then it is probably 12 volts or close to it. Regardless the Aux Battery Boost start should have cranked it if the battery was low. If you follow those steps I have listed it will help us a lot in guiding you. Let us know.

[deSanford]

My chassis battery was NOT charging while plugged into 110vac. So I added a trickle charge that charges the chassis battery when plugged into 110vac. This little "trickle" charge unit also charges my chassis battery when my solar battery charger charges my "house" batteries when dry camping or RV is in storage with NO hook ups.

[BandM]

Fixed Mike and all tanks for the tips. Turns out it was a broken ring connector on the solenoid. At first inspection it looked fine but when it loosened the nut it dropped out