Ok, I have used the search feature on the forums, and I say I think I might have the standard answer, but I would like to get an individualized, personal answer.
This just started today, which pisses me off because I bought this car 2 weeks ago and it didn't do it before today.
I have a '94 camaro 3.4. When I cut the car on the voltage pegs to 17 or 18 then drops, then back up, then drops, and sometimes stays at 17 and the headlights get really bright for a minute or so, then drops back to about 13 or 14. After I have been driving for awhile (about 5 or 6 miles) it stabilizes at about 13 or 14. Then the service engine soon light comes on, then after about a minute it will go off and everything is fine. What exactly is the deal? The engine light might be totally different, because I actually did notice that the second day that I drove it, but it only stayed on for a minute tops. Also, the when idling the temp gauge starts creeping up higher and higher (it normally sits a little below the middle mark). It hasn't overheated or anything, but I smell the infamous smell every time I cut it off.
Am I going to blow up something besides the battery if I continue to drive it like this? I really need the car for transportation to work, so I would really like an answer to this question as well. I am a young guy that has 0 experience in messing with stuff in cars. What route would I go about doing what you suggest? Please help me, the idle gauge creeping I can deal with. Pegging out on the volts is something I cannot.