Reader Question A few months ago i bought this car and about a month later the battery light started coming on. Finally on a trip the light started coming on it was like everything kept dimming down , so we replaced the alternator/regulator is built in and it didnt help the problem. (but i drive it like that). The light still comes on and every now and then it does that dimming thing. (as I call it–surging).
Well today I had to got a place over 1 1/2 away and it did fine most of the way with the light on but then started to do the surging thing and then when i got in my car to come home the battery was dead.
So we got it going and it acted up the most of the way home and we couldnt run the A/C or radio but then all of a sudden it acted fine but the light was still on and then on my way somewhere else (by this time it was dark out) I had my lights on and it started dimming down so much that I barely had headlights, but the weird thing was that it wouldnt stayed dimmed down –it would dim for a second and then be fine for the next second and it did that the whole way home–.
people think its the voltage regulator that is built into the alternator. the auto parts store checked it and said it was fine even though it shoud be putting out 14 volts but its only putting out 12 and they said the battery was fin. So if you can please HELP!!!!
It does sound like you have a problem with the alternator/voltage regulator. Before you do anything else though I would HIGHLY suggest you take it to an electrical repair shop, one that specializes in alternators and starters (you are bound to have one in your town) and have them do a complete electrical system checked ON the car.
You want them to test:
1. Load test battery
2. Check alternator output
3. Check for voltage drain
This test is quick and cheap and should be the first thing you do. Testing the alternator OFF the car is not the correct way to test the electrical system. I would also triple check the battery cables and connections to make sure they are good and tight and clean of corrosion. You should not be able to move the battery cables with your bare hands!
Keep me posted.
Austin C. Davis