Hello, I owned a class C RV, 1998 Chateau that was built from a Chevy van and with 4300 Vortec, 5.7L engine. While we came back from a camping trip, I noticed the volt meter needle decreaseed rapidly and the engine shut down. We rush to the nearest auto shop and bought a new battery and installed. The RV started and we drove home safe from it. The next day I checked on it and found out that the battery was dead. I jump started and run for 15 minutes to charge. As soon as I shut down the engine, it won't started again. This morning I replaced with a remanufacturered alternator. It doesn't work either. I junmp started and it ran, but won't started as re started the engine. I noticed while runing the battery show about 11.3 V. Is this a bad alteranator? Or is it a bad starter solenoid that drawn out the battery? Are there any other sources that could lead to the problem? Please help. thanks, KC

The alternator should be charging at 13.5 to 14.5vdc at the battery at engine idle. Some vortec engines had fuseable links running from the alternator.
You could have a bad ground or a cable may be shorted, a stuck relay or something not turning off and causing a drain also. You can run what is called a "parasitic draw test" to determine the source. I hope this helps.

The possibilities with an RV conversion van are numerous. There are usually all kinds of aftermarket equipment including battery isolation devices that can fail and cause the symptoms you are describing. The problem is that probably nobody can tell you exactly what to check because it would take a hands-on inspection of the vehicle to see what it is equipped with. It could be that something in the factory equipment has failed, or it could be that some of the aftermarket equipment has failed. I would recommend taking it to a local garage that is equipped to properly test your electrical systems to determine the actual cause of the problem.

Please also review this article:
What Else Could Be Wrong?