1970 Chrysler Newport over charging

[NWPT70]

Hey Everyone,

I am working on my latest 1970 Chrysler Newport 2 door. Currently the battery is charging around 15.40 volts. The epoxy backside of original firewall mounted voltage regulator showed signs of melting (see attached picture), so I replaced it with a new unit also seen already installed in the picture.

Can anyone give me some tips on what to check next? I understand the battery should be charging around 13-14volts.

I may try trying another voltage regulator under the chance the current replacement could be faulty.

 

[Yeahrightgreer]

What shape/how old is your alternator? If it’s the original - although they may last a while, may just be time with a quality replacement

 

[Xenon]

Charging for older car is 13.9 to 14.2....
The ALT is quite capable of putting out more...
If it is a dual field ALT be sure both fields are being used...
Make sure regulator is WELL grounded....
Make sure BATT is chassis grounded...
And I do not see the ground strap between the motor and the firewall...
Put one in if there s none..

 

[NWPT70]

Charging for older car is 13.9 to 14.2....
The ALT is quite capable of putting out more...
If it is a dual field ALT be sure both fields are being used...
Make sure regulator is WELL grounded....
Make sure BATT is chassis grounded...
And I do not see the ground strap between the motor and the firewall...
Put one in if there s none..

I just found out the screws I reused had a bit too much surface rust and weren't making a good enough ground. I replaced them with new hardware and it is now charging at 14.2ish. Thanks for those great tips.

 

[1970FuryConv]

What shape/how old is your alternator? If it’s the original - although they may last a while, may just be time with a quality replacement

Generally alternators fail and cannot put out enough volts. If the alternator's max output is less than 13.5V, it should be replaced. When an alternator is putting out 15.40V, that is evidence that the alternator is not the problem, but it's output is unregulated. Chrysler charging systems have a separate regulator, external to the alternator. Often GM has an internal regulator. You may be thinking of GM cars, in your suggestion to replace the alternator.