Overcharging! Help!

[carolinadoug]

I have a 1970 Satellite. The previous owner had installed a mid 70's electronic ignition and made some other "modifications" that left the engine wiring harness in a bit of disarray. The amp gauge as well as the volt gauge (also verified with a Fluke) were showing a significant overcharge. The amp gauge was pegged to the right and the volt gauge and meter showed nearly 18v at 2000 rpm.

I also found the alternator housing had a crack in the mounting area. I bought an engine wiring harness from Year one (modified for the electronic ignition), a new Autozone alternator, and a new voltage regulator from Year one. I also had the battery tested at Autozone. After installing all these parts the charging situation was the same. I took the alternator back to Autozone and exchanged it for new one and bought another regulator but I am still seeing 18v and a pegged amp gauge.

BTW - the alternator and regulator are Duralast replacements, no upgrades.

What am I overlooking??

 

[dryheat]

I'm certainly no expert but I did have a similar situation on my 74 Dart.

I finally traced it down to a crimped connection on the factory wiring that was grounding to the firewall. Added a little electrical tape and the problem went away. If I remember correctly it was on the output wire from the alternator.

 

[lewtot184]

if the regulator is grounded well the system will overcharge.

 

[ilm65]

HUH?????? I'm told you must be sure the voltage regulator is well grounded.

 

[Cranky]

HUH?????? I'm told you must be sure the voltage regulator is well grounded.

And that's very true too. Guys with freshly painted cars usually go through that problem too....

 

[67 B-body]

And the body ground must be in tact.... Does no good mounting something to a cleaned up firewall if the body isn't properly grounded!

 

[lewtot184]

when i had my 65 coronet painted the painter used a base coat-clear coat. he put a ton more paint on the car than factory. i started getting some voltage overcharging and eventually put ground pig tails on everything (regulator, control box, and additional battery ground). i felt like i was working on a 'vette! anyhow, no more charging issues.

 

[moparstuart]

I had the same problem earlier this year it was a bad alternator

 

[70Hemi]

long answer but will help you track down problem. use your meter to check all these out and than when you find the bad reading trace the probelm from there.
1. alternator- big threaded terminal 12v battery voltage key off, small spade terminal labeled (bat) 12v with key on, small spade terminal labeled (field) is a wire going from alternator to the triangle shapped regulator plug.
2. regulator triangle shaped plug- blue wire 12v with key on, green wire goes to field of alternator. housing of regulator MUST have a good ground to the body

step 1. unhook both small spade terminals to alternator and start car, it should not charge at all. if it does its a bad alternator.
step 2 hook up the small 12v wire to the bat spade terminal on alternator but leave the green wire off the field terminal, if it charges at all its a bad alternator.
step3 hook up all 3 wires on alternator, unplug triangle plug on voltage regulator, if it charges than the green wire from alternator to regulator is shorted to ground.
how it all is suposed to work-
the regulator varies the ground to the field wire of the alternator (the better the ground the more output)
the regulator has 2 wires
wire 1 blue- is the source voltage to the regulator so it knows what the system has (think of it like a volt gauge) it grounds through the housing to the ground. therefore if the housing isnt grounded good it will think it has low voltage and max out the alternator.
I hope this helps out, I know its a long explanation but it helps to know what the meter should read before you hook it up.
Good Luck
Dennis

 

[wannadrag]

I just rewired my BB mopar rod.With the newer electronic ignition, a orange or blue ECU box can be used and not a black 2 wire regulator and needs to have the correct newer style alternator.Worked for me.

 

[wannadrag]

Wiring diagrams at mymopar.com

 

[carolinadoug]

Found the problem! First I want to say thanks to everyone who made a suggestion. I followed 70Hemi's sequence to troubleshoot the problem and it failed step 2. While looking at the wiring diagram I noticed the alternator listed had 2 field connections and the one I had bought from Autozone had 1 field and 1 ground. I checked with the meter and sure enough it was grounded to the housing. I did a little research and from what I can find that model is for the older system with mechanical regulator (Autozone part number DL7001; this is the model the Autozone computer says is correct). The part number for systems with the electronic regulator is DL7516 - it has 2 "field" connections. I exchanged the alternator and the system functions perfectly.

Thanks again for all the help and beware if you shop at Autozone!

 

[Jay Lewis]

I have a 1970 Satellite. The previous owner had installed a mid 70's electronic ignition and made some other "modifications" that left the engine wiring harness in a bit of disarray. The amp gauge as well as the volt gauge (also verified with a Fluke) were showing a significant overcharge. The amp gauge was pegged to the right and the volt gauge and meter showed nearly 18v at 2000 rpm.

I also found the alternator housing had a crack in the mounting area. I bought an engine wiring harness from Year one (modified for the electronic ignition), a new Autozone alternator, and a new voltage regulator from Year one. I also had the battery tested at Autozone. After installing all these parts the charging situation was the same. I took the alternator back to Autozone and exchanged it for new one and bought another regulator but I am still seeing 18v and a pegged amp gauge.

BTW - the alternator and regulator are Duralast replacements, no upgrades.

What am I overlooking??

I know this is an old post but if anyone else has this issue her is an answer. Alternator and regulator need upgraded you can use both from a 1986 Chrysler Fith Avenue. Check out the article from hot rod mag. https://www.google.com/amp/www.hotr...ctronic-voltage-regulator-and-alternator/amp/