Thank you to those that have replied. Now for an update. This problem occurred last night, 170 miles from home, but at the last mile or two when restarting the van after a stop. I happened to have a code scanner with me so today I used it and it returned the code P0500. Upon returning home, I also saw that I had no speedometer, which was to be expected per the code I received.
Now for the interesting part--after a few miles of driving to return home (5 miles or so of the 170 mile trip), the warning lights went off, the AC started working, the air bag light went off and stayed off, the speedometer worked properly--everything is OK except that the Check Engine light is still on. (How do I reset it?)
I seemingly have a loose connection someplace. Hence, my question is--Is there a point in the wiring where this might be apt to occur? I cannot help but think that all is related since the Air Bag warning started to work properly at the same time.
For Further Explanation: The van is actually a Class B Camper Van. We live in Nebraska, but since December 1, we have driven to both coasts. The air bag problem started on the east coast, but only by the light staying consistently on. When we arrived in Nebraska and had the oil changed for the California trip, the light went off (not related I am sure). All was well until about 80 miles from our California destination when the intermittent Air Bag lighting and chimes started--on and off repeatedly. This continued until we reached our destination. However, the next day, all returned to normal. (also no Check engine light) It stayed normal all the way back to Nebraska. But, this weekend for a rather short jaunt, the intermittent Air Bag light and chiming started again and lasted until our destination, about 170 miles later--annoying, but livable. After reaching our destination, we restarted our van to go a few miles to another location and this is when many of the warning lights came on with the symptoms described in the original post.
The alternator is quite new (less than a year old) and all batteries are also quite new, so I do not believe it is a problem there. It is a heavy duty alternator and does a good job of keeping both the engine battery and the coach batteries charged.
This is a detailed explanation, but I think you can understand why I am quite vexed with the situation. To further the complications, whenever I am not on the move, everything seems to work OK, creating the hardest trouble shooting situation possible--trying to fix something that seemingly is working at present!
Again, all suggestions will be appreciated!