alternator gauge bouncing back and forth

[sonny martin]

65 dodge with 440 6 pack. alternator gauge bouncing back and forth. Put on new voltage regulator and had alternator checked .Alternator checked good. Car starting to miss and once
die. Any input would be most appreciated Thanks

 

[69a100]

Check grounds on that VR, which VR did you put in? Good Luck
charging system overview (imperialclub.info)

 

[Canadian1968]

does it bounce at idle ? or while driving

 

[Nate S]

Had a “good” alternator do this last summer. Put on a new one and it’s fine.

 

[AR67GTX]

The alternator gage was bouncing on my 66 when the motor would be reved up. Traced it to a fried wire in the harness from the alternator and a couple terminals burned/melted in the bulkhead plug assemblies adjacent to one another. I think when the motor was reved and voltage/amperage increased it would short between the melted terminals. I read on here once that each time your alternator gage jumps, a short has just occurred. I think he was right. I removed the wire harness from the alternator to the firewall before I discovered the melted wire. It was just like the insulation slumped off to the side and left the copper conductors more or less exposed for the entire distance - not burned or an obvious mess - just a conductor nestled in a ribbon of melted insulation. The harness as installed placed the melted wire on the bottom and it just wasn't obvious without close examination. And it was a struggle getting some of the bulkhead plugs out of the bulkhead receiver - the plugs had fused with the bulkhead around the shorted terminals. They were a mess. Say hello to a new wiring harness.

Hopefully you have a lesser problem.

 

[sonny martin]

The alternator gage was bouncing on my 66 when the motor would be reved up. Traced it to a fried wire in the harness from the alternator and a couple terminals burned/melted in the bulkhead plug assemblies adjacent to one another. I think when the motor was reved and voltage/amperage increased it would short between the melted terminals. I read on here once that each time your alternator gage jumps, a short has just occurred. I think he was right. I removed the wire harness from the alternator to the firewall before I discovered the melted wire. It was just like the insulation slumped off to the side and left the copper conductors more or less exposed for the entire distance - not burned or an obvious mess - just a conductor nestled in a ribbon of melted insulation. The harness as installed placed the melted wire on the bottom and it just wasn't obvious without close examination. And it was a struggle getting some of the bulkhead plugs out of the bulkhead receiver - the plugs had fused with the bulkhead around the shorted terminals. They were a mess. Say hello to a new wiring harness.

Hopefully you have a lesser problem.

Thanks I appreciate the info. I'll look at the harness.

 

[Tony Tee]

I had my amp gauge do the same thing. It was a broken winding wire in the alternator. Intermittent problems drive me crazy!

 

[sonny martin]

does it bounce at idle ? or while driving

does it at idle and driving

 

[sonny martin]

Check grounds on that VR, which VR did you put in? Good Luck
charging system overview (imperialclub.info)

i replaced with stock voltage reg for 65 dodge coronet

 

[sonny martin]

Had a “good” alternator do this last summer. Put on a new one and it’s fine.

did alternator gauge bounce around at idle and while driving ? Your saying your alternator tested good . Replacing alternator would be easy fix. I hate electrical problems. Thanks I appreciate feedback

 

[Nate S]

did alternator gauge bounce around at idle and while driving ? Your saying your alternator tested good . Replacing alternator would be easy fix. I hate electrical problems. Thanks I appreciate feedback

Yes. Battery still charged for the most part. Needle just bounced all the time. Swapped the regulator and no improvement. Then swapped to a rebuilt alternator and it became perfectly steady again.

 

[sonny martin]

update on gauge bouncing. found some wires in wiring harness where insulation had broken, put in new wiring harness, new starter relay, voltage regulator, ballast resistor .Wont start with key can jump with screw driver between starter and solenoid starts right up . ANY INPUT IS APPRECIATED. GETTING FRUSTRSTED

 

[AR67GTX]

Did you do any replacement or other work under the dash? I would double check the bulkhead connections for the new harness sections and make sure none of the connections slipped out of place in the plugs because they were not clipped in securely and backed out.