I just found and fixed a very vexing issue with the charging system. I had an issue with the chassis batteries not charging properly, they were at 13.9V one minute and then down the road would drop to 12.3V and then back again, until they stayed at 12.3 and lower. My inverter display also indicated a fault with a very high battery issue, it was disconnecting because the coach batteries were reading at over 17.7V and the Magnum inverter protects itself by disconnecting at over 16V. I was forced to run the generator to keep moving and was pouring water into the batteries. I suspected a sensor wire issue and replaced all the terminals on the alternator but no luck. Poking around I noticed a piece of threaded bolt on top of the coach batteries. That turned out to be the end of one of the terminals on the battery isolator. Apparently the jam nut affair holding the terminal from the alternator had fallen off and the terminal was acting as an intermittent arc welder as it bounced around severing the terminal stud. After removing the second nut and attaching the terminal directly to the isolator on the stub of the terminal all was well, no issues with the inverter and 14V on the chassis batteries. The isolator was mounted in such a way that it couldn't be easily seen or examined and a great deal of cursing was employed to access and fix the issue. Bottom line, periodically check the terminal connections on anything that has a nut on it and you can avoid paying someone else to do the job. It was a three fingers of my favorite libation affair.
