2013 E450 Sunseeker - Chassis and Coach battereies appear to be joined

[stevemoores]

Would it make sense that a 2013 on an E450 would have the chassis and coach batteries linked permanently.

After getting my motorhome out of storage, I only fitted the chassis battery, but was surprised to see that the interior lights still worked.

Then I disconnected the chassis battery and installed the coach batteries and the lights on the dash work.

In my old motorhome, these were totally separate systems.

This is an ex-rental, I've only had it one year and am wondering if they have somehow linked the batteries for renters so they don't run them flat?

I'll start tracing wires, but wanted to be sure that my thinking was correct before I went any further.

Steve

[Dp26]

Ex rental, anything could have been done to it...

[Garrette]

First, check the momentary switch, down low on the left side of the drivers seat. This momentary switch is used to join the batteries in the event the couch battery is flat. It will allow the couch to start on the house batteries. Easy to unplug the wires and test. You may need a new switch.

[Shredder]

Originally Posted by Garrette

First, check the momentary switch, down low on the left side of the drivers seat. This momentary switch is used to join the batteries in the event the couch battery is flat. It will allow the couch to start on the house batteries. Easy to unplug the wires and test. You may need a new switch.

You Better hope you COUCH doesn't start or you may have a hard time sitting.. Just kidding.

There is a main cutoff switch on mine by the stairs make sure this is turned off. Like the previous poster check the switch. If all else fails disconnect both coach batteries and see if you still have power. Reconnect those and disconnect the main battery under the hood and see if you have power. If you do then you really have a problem.

[stevemoores]

Thanks Guys, sounds like it's not normal, so I'll start tracing wires and checking switches as suggested. Appreciate the answers


As for DP26, if you can't answer, maybe don't. Perhaps your ignorant opinions would be better off on Facebook.


Steve

[poppytoymaker]

how does the momentary switch work?

[Ridenfun]

The momentary switch is a MANUALLY actuated button or switch that closes when pressed to connect the house batteries to the coach battery to allow the engine to start if coach battery is low. If it sticks closed the batteries are always connected, instead of just "monentarily" when it is being pressed.

Additionally there is another "switch" sometimes called a battery isolator that is actuated by a signal that the engine is running, hence alternator is charging. When you start the engine, this closes to again connect the coach and house +ve terminals to allow the house batteries to charge while driving. IF this sticks closed it could also cause the problem discussed. I had one years ago that froze in the closed position (ie connecting the two batteries) just from not being used, Hit it with a wrench and it opened but then wouldn't close when it should reliably.so was replaced. Mine have always been near the coach battery. Look for a wire running from the +ve post to a snall "box" which will have a similar size wire running back towards the house battery but also another usually smaller wire, which is bringing in the signal from the alternator that causes the isolator to close, hence connect the batteries.

[ScottBrownstein]

Originally Posted by Ridenfun

The momentary switch is a MANUALLY actuated button or switch that closes when pressed to connect the house batteries to the coach battery to allow the engine to start if coach battery is low. If it sticks closed the batteries are always connected, instead of just "monentarily" when it is being pressed.

Additionally there is another "switch" sometimes ....

Actually the momentary contact switch simply fires the battery isolation solenoid, just as having a charge voltage over something like 13 volts does. If you have a "boost switch" you have an isolator as well. Could be that it failed and someone just put both batteries on the same solenoid lug, rather than getting it repaired.

[stevemoores]

Good point about the Solenoid.


I have 3 cables to my battery (positive), one is thick and will be the starter, one goes across the front of the engine to the Power Distribution Center, the other goes down and underneath, I'm assuming this goes to the Gen Set.


I've not traced any cables yet, but both Genset cable and PDC cable are drawing 0.5A with nothing switched on (that I could see).


Not an urgent problem, but I'll have to spend some time with my meter when I get a free weekend.


Steve