batteries not charging

[cladouce]

Hello, I have a Four Winds 2018 with Mercedes chassis. I have 2 new house batteries and the don't charge when the engine is running. I can charge them with the generator but not with the diesel engine. The Engine alternator charges the truck battery only. Any suggestions?

[Grumpy Grampa]

Check all your battery box, and engine breakers, one may have tripped.

Good luck

[cladouce]

Originally Posted by Grumpy Grampa

Check all your battery box, and engine breakers, one may have tripped.

Good luck

thanks

[16ACE27]

Originally Posted by cladouce

Hello, I have a Four Winds 2018 with Mercedes chassis. I have 2 new house batteries and the don't charge when the engine is running. I can charge them with the generator but not with the diesel engine. The Engine alternator charges the truck battery only. Any suggestions?

If you research you will find this is normal for a Mercedes chassis MH as they don't allow connection to other electrical systems from their chassis electrical system.

[cladouce]

It is not permitted to have the generator charge the truck battery but it is possible that the truck alternator charges the house battery. I have seen it done with my motor home since 2018.

[Hooligan2]

Mercedes Sprinter chassis- The engine alternator should charge the both chassis and house batteries through the Trombetta Relay or the BIM. (Battery Isolation Manager)
My 2016 the Trombetta is under the driver seat and I have replaced mine.
Mercedes does not let the RV generator or shore power charge the engine/chassis battery.

[Hooligan2]

cladouce- I answered your PM but not sure it worked. The trombetta for my unit was 684-1251-012 12 volt. Yours may be different.. Be sure it is marked 12v/CONT for continuous duty. The relay only closes when the engine is running for several seconds, and should show alternator voltage on both large terminals +-14 volts.. There is also a 5 amp inline fuse on the control line for the relay.