Alternator Seems to be Charging Too Much

Is it possible that if an alternator goes bad it can charge too much? On my Ford F150 about three days ago my starter went out, (I figured- no big deal, its a 30 year old starter) and now this morning I went out to go to work and it would not start. It would not turn over. It would just have this repeated “click” noise at first, then nothing. I put the battery on a charger to see if it was charged or not and it was reading that it was very overcharged and the connectors on the charger were starting to spark. I let the battery sit about 20 minutes and put it back in the truck and it started.

As far as I know the battery is good because it did the same thing yesterday with a different battery.

Any help will be very greatly appreciated


If the starter wouldn’t turn, chances are pretty slim the battery isn’t over charged.

If an alternator is over charging it’s because the voltage regulator is bad. It’s a pretty simple fix on a Ford. On the back of the alternator is a sort of rectangle shaped electronic deal. That’s the regulator and brushes. You can take it out and install a new one pretty cheap, about $25 or so. Have you noticed the headlights changing brightness? That’s a good sign of bad regulator or brushes.

As far as it not starting, if the battery is good, chances are the solenoid is bad. Some Ford’s have 2 solenoids, some only 1. The first one is on the fender near the battery. You can check it by crossing the large poles with a screwdriver. Cross the poles and if it turns over then that solenoid is likely dead.

None of mine ever had the second solenoid, but there can be one on the starter on some of these trucks.


If the alternator is overcharging, the acid solution will boil out of the battery, and the battery will get hot. What reading did your charger give you that makes you think the battery was overcharged?

I think what happened is you had corrosion on the battery posts. Removing and replacing the connectors scraped off enough gunk to allow a good enough connection for the starter to work.