What can make a volt meter peg all the way. Alternator has been changed. If is not a bad gauge is there anything else it could be.
This is on an 1983 Trans Am.

 

What's the actual voltage?

[small font] maybe the gauge is telling the truth; or maybe, ... not? good place to start the investigation [/small font]

 

Charging at 14 volts.

 

If your volt meter shows 14v, and your gauge shows way above that then one of those two is wrong. Are you saying in your original post that you know that the gauge is not bad, or are you asking for other possibilities to inspect before condemning the gauge?

 

What is "charging at 14V"? Measured where? When?

Get 4 voltage measurements: directly across the battery terminals (NOT the connectors, if possible; the battery itself), between the big post on the alternator and the neg terminal of the batt, between the engine block and the chassis, and between a convenient "batt" point in the fusebox and the chassis.

 

I can't think of any way for system voltage to go high other than the alternator regulator failing high. I think you already figured out the alternator is regulating system voltage to 14V, which is in spec.


--> Probably a bad gauge. Maybe the spring broke and now nothing is resisting coil (needle) movement.