Help with '69 RR Ignition and charging

[bird blaster]

Found what the frayed wire was for --> my reverse light. Fixed now.

Waiting on Alternator help - thx

 

[bird blaster]

I found another older thread suggesting I could run a second line from the second FLD tab to the IGNITION side of the voltage regulator. This did not work. The wire overheated and started to smell...back to the drawing board. Still thinking single FLD alternator

 

[bird blaster]

Looking for more help.

I am still having failure on the charging side of the equation. I have checked and replaced the voltage regulator, alternator, ballast resistor. I fixed the ignition switch issue.

I'm left looking for wiring issues? Could my fusible link be fried? It looks normal so I am not sure. I also don't know how to get it out of from the black connection harness.

In an effort to look for any other fusible lines I looked at the other fuses on the car. They don't seem to be part of that system and they all look fine.

Looking for next steps.

THANKS!

 

[bird blaster]

Checked the fusible wire. Don't think it is this.

 

[RJRENTON]

Since you stated your car is a 1969, it would have had a 37 amp ROUND BACK, SINGLE FIELD alternator....unless someone replaced it with something newer, such as a 48 amp ROUND BACK dual field alternator using a Mopar electronic voltage regulator....or....a 50 amp SQUARE BACK DUAL FIELD alternator using a Mopar electronic voltage regulator. Please provide a few pix of the alternator, rear view if possible, and the voltage regulator on the firewall to get a better idea of what you have ....to better provide a diagnosis of your issues.....and a few more details about the systems operation. Could be something simple like a bad ground, corroded connection, bad diode in the alternator or maybe bad brushes in the alternator.......or the previous owner's lack of knowledge. BTW.... do you have a copy of the factory service manual for your year and model?
BOB RENTON

 

[bird blaster]

Thank you for your help. Yes I do have a copy of the shop manual. I was able to find online.

Here are a few pictures of the wiring. The current alternator looks to be a SQUARE BACK. The car came with a spare as well. Both pictured.

Please let me know what else is needed for pictures to be helpful.

 

[bird blaster]

 

[RJRENTON]

Thank you for your help. Yes I do have a copy of the shop manual. I was able to find online.

Here are a few pictures of the wiring. The current alternator looks to be a SQUARE BACK. The car came with a spare as well. Both pictured.

Please let me know what else is needed for pictures to be helpful.

View attachment 1475798

View attachment 1475799

View attachment 1475800

View attachment 1475801

View attachment 1475802

View attachment 1475803

Thanks for the the pix....it helps with explanation. The 3rd pix shows a mechanical (or up dated electronic voltage regulator) and subsequently a SQUARE BACK ALTERNATOR. These rebuilt aftermarket units can be adapted for use with your style voltage regulator, by GROUNDING one of the two FIELD CONNECTIONS on the alternator (it does not matter which field connection) which connects to the GREEN wire from the voltage regulator. The 4th pix shows, what appears to be, an unconnected field terminal on the alternator. This connection MAY BE GROUNDED thru the brush holder mounting screw.....which is acceptable....but confusing as it appears to be unconnected..... square back alternators have been prone to positive diode failures, due to inadequate cooling. A diode failure (open) reduces the alternator AMP capacity by a factor of two...or half the output yet the alternator will try and produce the 14.5 volt output voltage. IMO.....what you show appears to be correct. You could substitute alternator to see if your charging issue improves......
BOB RENTON

 

[bird blaster]

THANKS!!

So I am going to try a wire from empty field tab to the green side in the voltage regulator. This is correct?


Second option would be to see about getting a round back single field alternator and substitute it.

Let me know if I am understanding correctly.

 

[RJRENTON]

THANKS!!

So I am going to try a wire from empty field tab to the green side in the voltage regulator. This is correct?


Second option would be to see about getting a round back single field alternator and substitute it.

Let me know if I am understanding correctly.

ABSOLUTELY NOT......DO NOT ADD ADDITIONAL WIRE AS YOU NOTE. IF THE UNUSED ALTERNATOR connection is routed to the voltage regulator's green wire, it will SHORT OUT THE FIELD CONNECTION AND LIKELY DAMAGE THE VOLTAGE REGULATOR AND POSSIBLY THE FUSABLE LINK. Perhaps source a correctly rebuilt round back alternator.
BOB RENTON

 

[bird blaster]

Ok thanks!! I am glad I checked!!

So what is the way that I can use the current alternator?

 

[RJRENTON]

Ok thanks!! I am glad I checked!!

So what is the way that I can use the current alternator?

Not sure what you mean....."So what is the way that I can use the current alternator?" .....post a for sale ad on the site?
BOB RENTON

 

[bird blaster]

Not sure what you mean....."So what is the way that I can use the current alternator?" .....post a for sale ad on the site?
BOB RENTON

haha - ok.

I just meant can it be made to work. It sounds like no!

I am finding a single tab now. Nothing locally for me so I have ordered a single tab unit.

Remanufactured Alternator by ACDELCO - 334-2086​

Remanufactured Alternator - 334-2086 by ACDELCO on PartsAvatar.ca


I really appreciate the help. I will post update when I have it installed.

 

[RJRENTON]

haha - ok.

I just meant can it be made to work. It sounds like no!

I am finding a single tab now. Nothing locally for me so I have ordered a single tab unit.

Remanufactured Alternator by ACDELCO - 334-2086​

Remanufactured Alternator - 334-2086 by ACDELCO on PartsAvatar.ca


I really appreciate the help. I will post update when I have it installed.

When my alternators need work, i repair them my self. The AC Delco unit you show has a good reputation...perhaps you should also consider replacing the voltage REGULATOR...NAPA or Standard Motor Products markets one....~ $20.00....its the electronic replacement for the original mechanical voltage regulator....
BOB RENTON

 

[bird blaster]

Thanks Bob.

I have one of these. I will go ahead and replace the existing unit in case some how it was damaged.

https://www.classicindustries.com/product/1969/plymouth/roadrunner/parts/md2439.html

 

[bird blaster]

Success!!!

New round back alternator and voltage regulator.

New question. Ammeter doesn't read "charge". But it doesn't move down now. How do I go about problem solving this to have it show D/C more accurately.

Pic running and second with all lights on including interior and high.

 

[LowBikeMike]

On a properly operating system, the Ammeter should consistently stay in the center and not read Charge or Discharge. During starting needle will likely be on D side, and after starting briefly be on C side of center, but should settle in the center.

 

[bird blaster]

On a properly operating system, the Ammeter should consistently stay in the center and not read Charge or Discharge. During starting needle will likely be on D side, and after starting briefly be on C side of center, but should settle in the center.

For whatever reason it all works now. I did nothing. Staying on the C side of the equation all the time.

Thanks for everyone's help.

Now on to the idle stall issue when hot.

 

[RJRENTON]

For whatever reason it all works now. I did nothing. Staying on the C side of the equation all the time.

Thanks for everyone's help.

Now on to the idle stall issue when hot.

View attachment 1480912

Excellent results.....just a slight charge showing.....normal operation......
BOB RENTON