while plugged into shore power, the chassis battery should be about 13volts or greater....the next test I did was two part... it was a fast battery test, and charging system test..while hooked to the chassis battery , I did a load test..though the battery was low,... it still took a pretty good load...then, clunk.. the noise came from by the chassis batterys,.. and now the volts jumped to 13 volts... Houston!! we have have power...so with that test, I found out that yes the BIN was working,... and yes the battery was good...
something else wrong!!