so...
The valiant battery died. We jumped it. Drove for about 5 miles. Headlights slowly dimmed then she stalled. Pulled her off the road, hooked her up to donor vehicle, let her charge a bit. Then she fired right up. Drove her about 2 miles with headlights dimming to black as she makes it in the driveway.
In the driveway, voltage from alternator is identical to voltage between terminals. Okay bad alternator. Alternator replaced with new alternator. Now we get 14 point five volts from the alternator.
Valiant runs well for one week. Then dies completely after sitting for 2 hours. Valiant gets jumped again. She StartS right up. About 1 mile down the roAd, she sputters out and dies completely. Now she will Not jumpstart at all.
There is no clicking, no burnt wires. Battery voltage is 6.5.
Battery is less than 2 years old. Battery was charged full prior to installation of new alternator.
Need help... Any Ideas?

Yup, batteries don’t respond well to being drained dead flat. One or two complete drainings of a battery will kill it, and then it won’t hold a charge.
When you installed new alternator, voltage regulator upped output to 14.5v trying to charge a battery that was incapable of being charged.

You need a new battery, and should check all connections in charging circuit making sure they are clean, and not causing voltage drop. Make sure that voltage regulator and spark controller (orange box or like device) is well grounded with no voltage drop between them and negative battery terminal. Hopefully with clean connections your charging voltage will be more normal 13.6 to 14v.

Oh, where are my manners…

Welcome to the board. When you get a chance tell us about your Valliant, and perhaps post a photo of her.

_________________
67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

Prior to installing the new alternator the battery was Pulled from the valiant and charged comPletely on an external charger. My apologies for all of the capital letters. I am sending this message from a tablet and it is capitalizing the first letter and every usage of that letter in the sentence.
I am not fresh to the board. The valiant is a 1975 Plymouth Valiant custom. Slant Six of courSe. Less than 70 thousand original miles. This was my firsT car and I was a member of the board number of years ago. I then joined the army and the Valiants sat for several years. Now we're tryiNg to save the dream...

Hey welcome back anyway. Are you still a ground pounder?
This hard duty for a car battery, once the headlights dim to dark, dropping voltage below 11 v that battery has reached its limit causing plate damage that may not be reversible. Take battery to auto parts store for a load test and see if it has any reserve ampacity (ability to deliver amps) left, or it is toast.

_________________
67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

First get battery tested. If bad, replace. If good, Check for current drain, with ign off. It is possible the rebuilt alternator has a shorted diode, or something else is staying on.
Since you had the engine running, and then it died, evidently the charging system is not working. Even with a bad battery, if you jump start the engine, it sould keep running if the chargeing system is good.
I would suggest you take both the battery and alternator to be tested. If they check good, then more trouble shooting is in order.

_________________
Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

The valiant has a modern cd player with a memory wire. Drain should be minimal. Any other ideas? Ballast resistor was dark with channels cracked. It's been replaced. Any chance this could be a voltage regulator problem?

Chris,
Do you have a volt ohm meter, and test light?

Do you have an electrical diagram for your car?

There are only four items to test and or inspect that would be causing a problem: alternator, have it tested at parts store; battery, have it load tested at parts store; voltage regulator and its ground integrity; and all related wiring and connections looking for voltage drop.

Memory of sound system will drain a battery, but it will take a long time, weeks or months. I had a problem with my XM replacement Passport when turned off (display off only apparently) would continue to draw its full complement of juice in the LeBaron that would drain the battery in a week or so if not unplugged from cigar lighter.

Once you determine all charging system components are working correctly or have been replaced, and all poor electrical connections corrected by cleaning, replacing connectors or running new wire as needed with no voltage drop for voltage regulator to see, it should all work.

_________________
67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

Alright...
Replaced the volt regulator
Battery passed load test
All grounds and connectors have been cleaned, sanded with fine grit paper to bare metal, and coated with dielectric grease.
Cleaned parts include battery terminals, bat negative to block, top grounding strap from elec choke assist to chassis, and volt reg ground. Off hand we also replaced the distributor cap and rotor.
We fired her up and she sounds great but the ammeter is spiked across about 3/4 to the right. In my past experience, the ammeter should be near the center.
Ideas?

Was the battery fully charged , if not it is getting charged.

Richard

_________________
Part of Tyrde-Browne Racing

Battery was fully charged

Some of the newer voltage regulators are charging at about 14.8-15 volts. Yes that is too high, use a volt meter across the battery while engine is running see what you have.

Richard

_________________
Part of Tyrde-Browne Racing