It seems that Ive got an electrical prob here, the headlamps are running of off battery power and not the alternater....i can tell cause of the dimmness in the dark, the fact that the 1st night the fuse blew, and they are bloody weak. also when i switch the voltimeterback and forth and turn lights on and off I can see the draw on the meter... ANY IDEAS appreciated, I drove 40 miles on rte 30 in Arkansas inda dark with the roof searchlight on the shoulder line! ouch! my neck is stiff...

Headlights are supposed to run off the battery; the alternator is supposed to keep the battery charged.

The problem is with the alternator or its connection to the battery. Don't overlook ground wires' connections to the chassis.

Before running any diagnostics, clean all the chassis ground connections, connections to the isolator, and the positive battery terminals as well, then:

Check battery voltage on both the house and engine batteries with the engine off and then with it running. If neither battery increases voltage, there's an issue with the alternator. If it increases only on the house battery, there's an issue with the isolator (and there still could be an alternator problem).

the voltimeter on the dash indicates that the polarity is reversed somewhere! its pinned in the negative.. i switch it to test and it hits 13v and than to house it pins neg. than switch back it is all neg. but back at the control ctr it says 80% chassis and 100% coach thats battery, I dont have any of my tools here and the tool box that the seller put in the basement on his special shelf, has NOTHING in it he said it was a gift!thanx... boy he didnt like parting with n e thing!