[rheavn]

I replace my batteries, both house & chassis every five years and have avoided battery issues with this maintenance schedule.

The "Check alt" light started about 2 years ago.  After Newell told me batteries were the only thing that could cause this to occur, I had the batteries load tested and they tested good.  Since then I have replaced all the batteries, on schedule, and nothing changed.  I have also changed my merge switch which I do on a 2 yr schedule.

"I am NOT a fan of charging the house batteries with the alternator."

If you are driving without the genset on, isn't the alternator charging both battery banks?  I thought this is what the battery isolator allows. 

I do understand that the triangle belt setup is not the best.  I have run air ducting to the rear of the alternator to increase cooling and I don't start out without the batteries being in float mode prior to starting the engine.  I have also put a 3 13/16" pulley on the alternator--came with a 3 1/4" pulley.  This has eliminated belt squeal.

I get this "strange issue" when I am driving and Suzy starts the genset prior to stopping.  Now I understand why.

Thanks again to all for your info & patience with someone who has a lot to learn on electricity.