Flicker

[OneMoFord]

I have to admit that electrical in auto's has not been my strong point over the years. Here is the thing, Battery and alt hooked
up and the lights flicker, When I disconnect the battery they seem normal,no flicker. The alt and reg have been replaced as well as the wires goin from reg to alt. Whats up that little red light on the dash to the left of the key? Someone tried to explain it has to do with resistance or something. And it does not light. Any thing come to mind? Thanks John.

[fordman]

for now ignore the red light beside the key. the bulb is probably burned out or its unhooked. it is a brake warning light. the headlight switch has a breaker in it. that when the breaker gets old and hot it will let the headlights turn off and then back on as the breaker rests. but my though it you may be loosing the ground when they flicker.

[OneMoFord]

Hey Fordman,
Thanks for the reply, You would think that the charging circuit would be at fault, Why then when I disconnect the battery does the voltage stabilize? So you think the headlight switch? John

[fordman]

its not the headlight switch.

so i guess i read that wrong before. your saying they flicker all the time when the battery is hooked up. that would mean that the lights are echoing. or showing the pulsing of the alternator into the battery. i think this is what is happening. i havce heard of this before. and i used to know what the fix was. but now i have forgotten. let me think about it. it might come back to me.

[OneMoFord]

Yes that is what is goin on I think. Which would make sense, I did the test jumping the reg, test the alt for voltage. I dunno, Like I said I am not the best at this stuff. Its gotta be something simple I hope but in my case probably not. We,Us,All will get it right I am sure. John

[70_F100]

Just because the alternator and regulator have been replaced, that doesn't mean either is good. New parts defective right out of the box is not uncommon in this day and time.

The lights are steady with only the battery hooked up because the voltage is steady.

The flicker comes from pulsing of the charging system, as already stated.

Take your truck to one of the local auto parts stores and have them check the charging system. Most of them will do it for free, and it beats chasing your tail.