Electrical ghost

I have a 1986 Ford Ranger that the battery light comes on and all lights get bright at 900 rpm on acceleration, and all lights dim and light goes off at 900 rpm on deceleration. I have replaced the battery, alternator and starter since getting the truck. I have also run ALL the wiring and found only 2 breaks which were repaired. I have had to replace headlights 3 times in two weeks, due to them blowing. Any help would be appreciated.

Did you try replacing the voltage regulator? It’s seperate from the alternator.


Yep, classic voltage regulator. Just did one on my Audi TT. Replace that and I’d bet you’ll be good to go. Do it soon too, I think it can damage the alternator if it isn’t working properly. Or maybe it was the other way around… either way, replace it.

Voltage regulator on this truck is built in to the alternator. Cant change independently. Alternator checks out OK

Voltage regulator… But in the Ranger i THOUGHT it was IN the alternator… Dodge is usually the only one to leave the regulator outside of the alternator… No?

It IS classic Voltage regulator scenario nonetheless… I will look up where your regulator is… OUTSIDE of that this can be a ground wire issue also. Check your batt connections AND the grounds…the ground is VERY IMPORTANT Sir


I know that the 1989 Mercury Sable I once owned had an external voltage regulator.