Headlights Burned Out
 

I was leaving a friends the other night and he stopped me and said I had a light out.I got out and tapped it and wiggled the connector,didn`t help.Oh well,I figured I`d drive home on Hi-beams.Before I was through the gears,the lights flickered and both went out.So,I quickly hit the dims and same thing,flicker,no light.I had to turn around and go back and borrow a vehicle to get home in.The battery will run down overnight,so I`m disconnecting it.The battery feels warm when I do.What kind of electrical problem could this be?Some thing is shorted,I guess,and there must be too much current in the circuit.Has anyone run intoa similar problem.This is a`72.

Bingo - I've never had it happen, but it sounds like your voltage regulator is putting out too many volts - that would account for a warm battery and blown out bulbs. Do you have / can you borrow a VOM to check the voltage? I'm not sure, you may not have an external regulator - it may be built into the alternator.

Two things...
 

First, most common problem is a bad voltage regulator(internal or external). Charging voltage as high as 17-18v will pop some bulbs! Second is bad diodes in the alternator will allow AC voltage to pass through and most DC componants don't like it. Bad diodes will kill the battery in two ways. Diodes will have a draw when engines off and AC voltage will fry it also.
Either way, you replace the alternator!
Scott

The draining of the battery overnight is another sign of a messed up charging circuit.

Thanks,that was quick!It`s still got the external voltage reg.Nothing else is burned out,yet.I`ve driven it a little since and even with the parking lights on some.I`ll test that out.What`s the benefit of goung to a one wire/internal set-up?Less wiring?It seems everyone I know goes that route.

screw the one wire, just get a GM 3 wire. Cheaper, better, easy to find, cheap to replace.

I had the same thing happen to me. Only I was 2 hours north from home. A guy that had saw me at a car show that morining 2 hours south noticed my truck anmd took me to his shop. We found the lights in his 55ish ford were the same T3's. Well I made it home with one low beam left.

It was the Alt I changed it no more problems.

Here is some info. if you want to up grade to an internal regulator alternator.
http://www.chevelles.com/techref/tecref14.html
http://www.madelectrical.com/electri...elcoremy.shtml

WOW ANDY... ARE WE A LITTLE OPINIATED & JADED THIS MORNING??? I'VE GOT ONE WIRE ALTERNATORS IN ALL THREE OF MY TRUCKS, & THEY WORK GREAT. I JUST BOUGHT A 135 AMP ONE WIRE ALT. AT THE H.A.N. SWAP MEET FOR $55. IS THERE A REASON YOU FEEL THE WAY YOU DO?? OR IS THIS SOMETHING YOU'VE HEARD?? I'VE HAD NOTHING BUT GOOD EXPERIANCES WITH THEM & HAVE BEEN USING THEM EXCLUSIVELY FOR FIVE OR SIX YEARS. MAYBE YOU KNOW SOMETHING THAT THE REST OF US DON'T. HOW ABOUT ENLIGHTENING US?? JOHN

Here's an article about 1 vs 3 wire. Based on this article I went with a 3.

Hmmm, can't see the article? :confused:

Nope, not there. :confused:

http://www.madelectrical.com/electri...hreewire.shtml
Here is some info. comparing 1 wire to 3 wire alternator.