nervous Needle

[jim]

Working on bosses 67 Cuda. He is complaining about the alternator needle twitching.
Alternator is charging right and has a aftermarket electronic regulator. Is this the nature of this system? Where would I need to start? Thanks for info

 

[ChrisPerry]

Is it just the needle twitching or are the headlights pulsating also? Is it just at idle or even when at higher rpm?

If just the gauge, I'd start with the instrument cluster grounds.

If headlights also flickering, check the connections from the regulator to the alternator, alternator to battery, and that the alternator and regulator are grounded well.

 

[omahamoparguy]

could be one of many reasons for the twitchy gauge. the 67 has many connections to go through in regards to the alternator gauge [amp gauge]. One big problem area is the bulkhead connection. Another area could be the newer V/R. If you had a good quality V.O.M. meter, you could check voltage drop for bad connections. If you have a newer alternator with alot more amp rating, this could also be a problem as the old gauge might not be able to compensate for its needs. {remember an alternator uses electricity to make it work] Another problem with the gauges in the old mopars is the electro=mechanical regulator that operates the gauges {although this maynot be applicable to the amp gauge but it could cause voltage spikes in general that might affect the amp gauge.} then also it could be the gauge itself being that it is 48 years old. Alot of guys bypass the old amp gaue in favor of a voltmeter. the mopar gauge setup tends to be unreliable after time. FWIW

 

[nm9stheham]

Just how 'twitchy' is it? It is going to move some normally as RPM's and loads change. It is not going to act like the modern car voltmeters; it an ammeter and its normal indications are different than a voltmeter. Also going slightly negative is normal for any ammeter if the car has been driven for a while, and then it goes to idle, or the lights are turned on.

If it moves, say, 1/4 of the scale back and forth with the blinker for example, then there are connection issues.

The gauge voltage regulator in the dash would not likely ever have any noticeable effect on the ammeter.

 

[Rapid Robert]

I would not shotgun a new alt for it but instead sub in one of your used ones & see if it clears up. First tho you might check/clean/tighten (if needed) the brushes/brush holders. Holler how it turns out