Issues with chassis battery charging

[Mo_Mike]

I am not sure how to troubleshoot this. When we took delivery of our VEGAS, everything seemed to work fine with the charging of house and chassis batteries. We keep the coach plugged into shore power at the house.

We went out to start the coach one time and the chassis battery was completely dead. (This while the coach was on shore power) We tried the emergency start to no avail. I connected an external charger to the chassis battery and heard a series of relay clicks so I powered down the charger. When I powered the charger back up, no clicks and the chassis battery was taking the charge, At this time I noticed the 100 AMP breaker under the hood was thrown (with the yellow "flag"). I reset the breaker. After the battery was fully charged, everything seems to work again. I monitored the voltages at the house and chassis batteries and was seeing 13.1 volts at both.

Now, today, I had the coach plugged into shore power and started the coach. After that, I am seeing 13.1 at the coach batteries, however I am seeing 12.1 volts at the chassis. I disconnected and reconnected shore power, disconnected shore power and started the generator, still not seeing the 13.1 volts at the chassis battery.

Not quite sure where to go next on this. It appears to be a relay issue, but not sure where or which one. Any help on this would be GREATLY appreciated

[petew]

I was told by the dealer that when plugged in to shore power the onboard charger takes care of the house batteries but not the engine start battery.
As such I keep my 24.1 on the shore power cord but also have the engine start battery plugged into a battery tender which is a small maintenance charger.

Don't know what popped your breaker but can tell you that with shore power and the battery connected I have had no problems with my rig.

[scrubjaysnest]

Ours never charged the cranking battery on shore power unless you got lucky and hooked up before the B.I.R.D timed out. After looking real close at the wiring vs wiring diagram I moved the coach battery lead, the one with the fuse, from the cranking side of the Trombetta to the coach side of the Trombetta. Now it works as specified including when the solar to the coach batteries gets above 13.1 volts.

Prior to moving the wire; I had pulled the fuse once and over night the cranking battery went dead.

[Mo_Mike]

Well, found out how to apparently get the chassis battery to charge from shore power. Disconnect shore power, start the engine, then turn off engine, and reconnect shore power.

Now the chassis and house show 13.1-13.2 volts. I am guessing it takes power at the chassis battery being more than the house battery to throw the relay. Guess it is time for a call to Thor.