A weak battery will cause ALL KINDS of problems, if only because the different computers on the car are set to quit working at different (8 to 10 I think) nominal volts.
A good battery will recover a partial charge by itself, if it's not too cold out, while just sitting. Might be enough to get you going. But after you start the car if the battery is not charging then all kinds of stuff can happen, including a low-voltage shutdown. You know, we may be onto something here. COnsider trying one or more of the following:
- with the engine OFF see if you can move the alternator pulley with your hand. Do not remove the belt. If the belt is tight enough it will be nigh impossible to move the belt. If the belt tensioner is loose, the pulley can be squeeked around under the belt. Replace tensioner (I don't think they can be tightened) if the pulley can be moved by hand with the belt on.
- have you looked at the battery? If you have an OE battery it will have an "eye" - if the eye is not green your charge is low. If that is the case we have to figure out why. Consider connecting a known good battery to the Riv via jumper cables,see if it starts up and behaves, if your battery is low.. Also while you have the seat out, clean the battery terminals and make sure the vent is hooked up right. And make sure acid is not eating the battery tray. .
- Might be the alternator is shot. They do not run forever. I am on my 3rd. Neither failed electrically (they were both OE Reman Delco's) but both had bearing failures. They squealed like stuck pigs. Maybe you're "lucky" and you got the one with electrical failure. I replaced my alternator first time in 2001 (less than 70,000 miles) and second time in April '07 at ~164,000 miles.
Yeah, the electrical thing explains a lot.