I have a 1998 Cadillac DeVille. The car started and drove fine then all of a sudden the Battery Not Charging message came on, then the Service Charging System message, then the battery symbol, then the Air Bag symbol, then the Anti-lock brake symbol. I pulled into a parking lot, turned off the car, and then it wouldn’t start at all. AAA changed the battery, but now the Battery Not Charging Message and the Battery symbol stays on with 1-2 seconds off about every 5 minutes. I can’t see the voltage display when the message is on the dash display so I don’t know if the voltage is dipping or not. The car seems to start and run just fine with the messages on, but I’m afraid the battery will be drained and leave me stranded. The intermittent nature makes me wonder if there is a loose wire? rather than the alternator. I am on the road at a conference – 2 hours from home. Thoughts?
Check the alternator drive belt, make sure the tension is correct. You might be able to tell it is slipping a little just by looking at it while the engine idles. If the alternator isn’t turning at a steady rate, that can cause the warning light to turn on and off. It could indeed be a loose wire or a fuse problem or the alternator is plumb out of electricity, but those are going to be hard to find unless you have some experience with your car’s charging system arrangement. And beyond just a faulty alternator, aren’t a common cause for this problem. On some vehicles – this usually applies to newer cars but could apply to yours – there engine computer involvement with the charging system. That would more likely be the problem compared to a loose wire between the alternator and battery.
You are wise to suspect a problem remains.
Good! Now you can perform crazy experiments. The only one I like is connecting a jumper wire from the engine block to the fender. Somewhere not near moving parts is best. If the situation improves, there may be a bad ground. You may need a new negative battery cable or something like that.
This is usually too simple to work but it has worked for me in the past. Cadillac, Chevrolac and Maverack.
I think you will need to replace the alternator before driving home. Don’t expect to find a loose belt or a battery cable that has fallen off, you would have had more symptoms.
Yeah I think your alternator has gone south too. Driving home from school 200 miles one night, my generator went out on my 59 Pontiac. With 100 miles to go, I stopped and got my battery charged and had a hamburger. When I pulled in at home my lights were very dim but I made it until I could replace the generator the next day. So if you have to go, I’d make sure the battery is fully charged first, keep everything else off that draws power but on the new cars it can be a crap shoot. Might make it might not so bring a lunch and phone.