Electrical problem
Thread Starter
Le Mans Master
Joined: May 2002
Posts: 5,084
Likes: 786
From: Lebanon Township New Jersey
Electrical problem
I've had this same issue with 3 different alternators in my 77. The current one is a new AC Delco unit. The problem is, with headlights on, the volt gage will move back and forth from 13v to the red area then back again. As it moves, the headlights and dash lights change brightness, kind of flickering. Same thing with high beams on. Gage moves with headlights off too, but not so extremely. Nothing else is affected, ignition is good, charging is good.
Any idea what's going on?
Any idea what's going on?
Le Mans Master
Joined: Oct 2002
Posts: 7,098
Likes: 378
From: Las Vegas - Just stop perpetuating myths please.
I'm sure u have a hand held voltmeter and can read it for voltage. Since the batt is right next to u hook up your hand held to the batt terminals and drive the car as u compare the hand held to the installed voltmeter. If they don't track together the installed meter is bad or not connected correctly. If they both track then the charging system is disfunctional or something is loading it like a loose short or ground.
Good luck.
Good luck.
Le Mans Master
Joined: May 2003
Posts: 8,870
Likes: 3,544
From: Fernandina Beach FL
2023 Restomod of the Year finalist
2020 C3 of the Year Winner - Modified
If the headlights are getting brighter- the voltage is indeed going up...the flickering might be AC being introduced as it sound like the alternator is toast..
Get you meter- turn it on AC -yes AC and turn on the headlights w/ the car running- if it's showing more than a few thousands of a volt AC- then the diodes are shot.
Richard
Get you meter- turn it on AC -yes AC and turn on the headlights w/ the car running- if it's showing more than a few thousands of a volt AC- then the diodes are shot.
Richard
Race Director
Joined: Mar 2003
Posts: 11,608
Likes: 778
From: Eustis ( Area 51 Bat Cave ) Fl
It would be hard for me to believe 3 alt all have the very same issue so yeah likely some place else, headlights on, big load, but start with what cardo0 said place a volt meter at the battery see if it mimics the dash gauge, if it does which I think it will then you have a loose connection or even a low level short, check all the connections I had a ground lead on my trike causing a hard starting problem that wasn't easy to at fist check tell was loose.
Race Director
Joined: Mar 2003
Posts: 11,608
Likes: 778
From: Eustis ( Area 51 Bat Cave ) Fl
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Thread Starter
Le Mans Master
Joined: May 2002
Posts: 5,084
Likes: 786
From: Lebanon Township New Jersey
All pulleys are stock size and no extra stuff being powered off the alternator. Need to check a few things with the meter as suggested, but keep thinking. Thanks.