I just picked up a 98 Explorer XLT that had been sitting unused for about six months. I had to drive it from the SF bay area to Orange county, which is about a 400 mile drive. When I first started the vehicle, the alternator charging light was on and the voltage was definitely low (running on battery only).

I popped the hood, found a bird's nest under the hood and bird poop everywhere but nothing obviously wrong and no broken wires. I stuck the battery on a charger and prepared for an extremely unpleasant journey home on just the battery.

After about 15 minutes of driving, the charge light went out and everything seemed back to normal, voltage came back up. To me this sounds like one of two things:

1 - I'm a huge lucksack, or 2 - The voltage regulator is going bad on the alternator.

Could it be something caused from disuse (like bird droppings in some contacts)? Basically, is this something I should plan on replacing 100%? It's a Remy alternator that was changed out about six years ago.

  • 1
    I like the idea of "lucksack" personally. It sounds like there may have been buildup (like oxidation or something) on the brushes/contacts which could have prevented it from charging, but after a bit of use, wore to clean spots which allowed it to start charging. Really, I don't know as this is kinda weird, but if it continues to work and the voltage output looks good (13.5-14.2vdc arena), I wouldn't worry about it until it completely gives up the ghost. Commented Oct 4, 2018 at 20:19
  • I believe the light only indicates voltage, from which you can try to guess if it is charging. I think you are lucky for now but will need an alternator ; age does not mean much , I had a 300ZX that would burn up an alternator each year ( they placed it too close to the exhaust). Commented Oct 4, 2018 at 20:26
  • Another possibility is a dead battery, or a marginal battery from sulphated plates that have been sitting idle for too long.
    – SteveRacer
    Commented Oct 5, 2018 at 4:36


You must log in to answer this question.

Browse other questions tagged .