Coach battery charging while underway

[Jim & Mary]

I've noticed while en route back to Oregon, our coach batteries will heavily charge after being plugged into shore power after our day's trip. We've never seen this before, perhaps the TV alternator is not charging them while underway. We have a residential fridge, which draws less than 2A AC (probably about 20A DC). The F350 has a 225A alternator which should keep up the battery charge with no problem. Anyone got ideas, or has anyone else experienced this problem before?

[Jim & Mary]

Also wondering how the charge line gets from the 4 square box by the pin box to the battery compartment. Can't find on any drawing. Or does it go directly into the converter box? Can't find that either.

[bergeman]

I had a similar problem with my truck not charging the RV. Ended up being a blown fuse in the truck. The rest of the connections were working, lights and brakes, just not charging.

The ultimate source of the problem was a shorted wire in the box where the tow cable was attached.

[Jim & Mary]

I was able to verify charging voltage present at the 7 pin receptacle in the truck bed. Voltage when engine running 14.63VDC