71 roadrunner not enough power to charge the battery

[SirSharker]

Well, I got stranded with a dead battery. Nothing too odd on the drive. Battery tested out with some volts but was dead charge.
Jumped the car to start and pulled negative. Car stopped immediately. Figured it was the alternator. Bought a new one even though the old one tested good.
Car still stops when I pull the negative. Figured it was the voltage regulator, replaced.
Car still stops when I pull the cable. Looking for ideas please

 

[Photon440]

Pulling the battery cable can be hard on the alternator diodes. It was fine 60 years ago with generators.

 

[70chall440]

Couple of things,

1. make sure you have a good ground on the VR
2. closely check your cables

 

[WP29440SE]

get yourself a multi meter and stop pulling the battery cable lol

 

[Don Frelier]

Check bulkhead connector

 

[SirSharker]

Charging battery. I do have a multimeter

Couple of things,

1. make sure you have a good ground on the VR
2. closely check your cables

I sanded down the firewall before adding in the new VR and wire brushed the bolts.
I don't see anything in the cables, ground iis to the front of the car and to the engine mounts.

 

[SirSharker]

Check bulkhead connector

More details please

 

[SirSharker]

get yourself a multi meter and stop pulling the battery cable lol

Once the battery is charged I can test more.
What should the output be of the post in the alternator?
Should there be a current on either of the other two wires? And should it be in the connector or on the post?

 

[tonysrt]

There should be ground cable wire going to the engine. Small blocks to the head b & hemi motors to the front of the block.

 

[SirSharker]

14.6 to batt while running
Still climbing, up to 15.19
13.5 at rea

 

[WP29440SE]

14.6 to batt while running
Still climbing, up to 15.19
13.5 at rea

View attachment 960230

you are looking for 13.8 to 14.2 while running at the battery clamps. the voltage regulator relies on body grounds from the battery to the body. make sure there is good clean metal to metal contact at all grounding points.
it may read high at first if the battery is low.

 

[YY1]

Could be a bad diode in the alt.

 

[Ernie ingling]

Save up your allowance and buy a new battery

 

[MoparLeo]

The alternator is not intended or designed to charge the battery. It only maintains the charge and powers the rest of the cars electrical demand. The battery is to start the car and excite the diodes in the alternator to induce a magnetic field. Dead battery, dead alternator. Slow charge the battery to full charge. It could take several hours. Test to at least 12.6 volts at rest. Load test pulling a 50% load. Should maintain 9.5-6 volts under load. If it doesn't, needs new battery. You can't check an electrical system without having a fully charged battery first. Otherwise all other test are not going to be accurate.

 

[SirSharker]

Save up your allowance and buy a new battery

Do you really think this is a helpful reply?

 

[toolmanmike]

Do you really think this is a helpful reply?

Other than bad wiring or ground issue that's all that's left.

 

[toolmanmike]

Charge up the battery and stop by Advance Auto and have them test it. They can probably test the alternator output as well. If the battery is ok and the alternator output is proper you know the regulator and that wiring is working and proper. Charging and starting system diagnosis always starts with a fully charged battery.

 

[SirSharker]

Charge up the battery and stop by Advance Auto and have them test it. They can probably test the alternator output as well. If the battery is ok and the alternator output is proper you know the regulator and that wiring is working and proper. Charging and starting system diagnosis always starts with a fully charged battery.

Had AutoZone fully charge the battery before the previous post. Load tested the battery too. All checked out green.
The test above where the volts were over 15 at the battery was with the fully charged battery. I have checked all the grounds, reseated each of them and I still get a really high read at the battery. Going to take her for a ride tonight and see how she does with a few miles. Either the power will balance out or problem will show up in a different way. Will retest the load and post.
I appreciate all the helpful advice!

 

[toolmanmike]

Had AutoZone fully charge the battery before the previous post. Load tested the battery too. All checked out green.
The test above where the volts were over 15 at the battery was with the fully charged battery. I have checked all the grounds, reseated each of them and I still get a really high read at the battery. Going to take her for a ride tonight and see how she does with a few miles. Either the power will balance out or problem will show up in a different way. Will retest the load and post.
I appreciate all the helpful advice!

15 volt output might blow your headlights out. I had a badly grounded regulator and it was charging over 15v. Pulled the headlight switch and POOF On my other car I always had over charging issues. Tries 3 different regulators. My buddy got a hold of a genuine Mopar regulator and that fixed the issue.

 

[Nacho-RT74]

The alternator is not intended or designed to charge the battery. It only maintains the charge and powers the rest of the cars electrical demand. The battery is to start the car and excite the diodes in the alternator to induce a magnetic field. Dead battery, dead alternator. Slow charge the battery to full charge. It could take several hours. Test to at least 12.6 volts at rest. Load test pulling a 50% load. Should maintain 9.5-6 volts under load. If it doesn't, needs new battery. You can't check an electrical system without having a fully charged battery first. Otherwise all other test are not going to be accurate.

Say wha?

of course is intended to keep the battery charged and source all the car demand BUT can get a battery charged too. Just need to be made with awareness.

Sure being at home with a death battery is better to make it properly with a charger, but on the road you can charge it with your alt. If ammeter comes too high into the ammeter, turn on lights to get the load going to batt reduced.

and of course if you are sure about the wiring conditions health. Bad bulkhead paths will melt with the excess of load.

A straight jumper wire between alt post and batt can be also added to help on the process after check the ammeter reading.