Alternator Question - Over Charging??

[mikeynags]

The following done to a 1970 Plymouth roadrunner.

Installed new Autometer Voltmeter and it shows 14.5 volts at idle, 12.5 @ idle with the lights on. When you bring the RPMs up it goes to almost 16 volts on the gauge. Replaced both the alternator and the voltage regulator at the same time and I am still seeing the same result. Is this just typical for an old mopar or do I have a potential electrical problem? It seems a bit high to me. The built in gauge shows a bit of a charge (10-20AMPS) after you first start the car but once the car warms up the gauge is in the center between "D" and "C". Also, I measure about 12.5 volts @ idle right on the battery and about 14 volts if you bring the RPMs up. Is it a bad gauge or do I have something else going on?

 

[dantrap]

Hey Mikeynags, I have run the blue DC/Mopar performance constant current regulator (1970 style 2-pin) for years with a Masterpower Alt and upgraded wiring on my 69. I also use the Autometer gauges and it reads 14.5 at idle, which i believe is correct. My car behaves the same as yours without any issues. I did measure the voltage with a handheld meter and it matched the gauge.

In the old published info they used to tell you not to run the CC regulator on the street. However with all the added power devices added to my car overs the years, msd, twin ele. fans, etc, i have had no problems. I do know you need to be 1.5 to 2.0 volts above 12 to charge the battery. Has any one else run into this?

I believe its common, if your using the blue solid state constant current regulator.

 

[mikeynags]

Thanks for the reply. I am running the the stock black regulator. The weird thing is that the gauge is reading higher than if I put a voltmeter on the battery. Where did you connect your Autometer volt gauge? Did you come off the fuse block as well?

 

[dantrap]

Hey mikeynags, i did it so long ago i will have to look to remember. I will get back to you.
It will always by higher than batt voltage, like 1.5-2.0 i believe.

 

[dantrap]

http://www.moparts.org/Tech/Archive/elec/21.html
try this link, it will help you out.