Alternator not charging house batteries on my 2009 Holiday Rambler Neptune.

SOURCE: Electrical problem in motor home

yes you have a short and your on the right track.
with your test light in line telling you have a short we need to start removing fuses to fine the circuit that is the problem let us know what circuit and then we can help.
later paul

SOURCE: DEAD BATTERY

should be something simple like a loose ground or a hot wire touching somewhere that is causing the battery to drain down

SOURCE: help with fuel pump location 1982 holiday rambler.

It is in the tank. You need to drop tank and test voltage of wires going to pump to see if it is in fact the pump. Clean the tank if you replace pump. Look at the pump on Autozone.com

SOURCE: battery charge light comes on a few minutes after car starts

Couple of things to check, first this may be nothing more than a belt that has loosened or stretched after the install.There should only be about a quarter of an inch stretch in the belt between pulleys. Caution - only check with engine stopped!!! The alternator causes a strong resistance when it is producing electric power, so slippage is to be checked first. Second, if the battery light comes on and off; it maybe acting in error. Get a multi-meter and check the battery voltage with car and ignition shut off. With the meter set on 12volt bat, place the black probe on the negative side of battery or ground and the red probe on the positive side of battery. If you get a reading of 12.66 v the battery is being charged and is full. If you get 12.45 you have a 50% charged battery. If less the alternator wiring needs further checking into as there maybe issues with wiring or the alternator itself. Hope this helps.

SOURCE: Alternator & battery test good...alternator is not charging bat.

you might check the fuses and battery cables