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Dodge Dart/Plymouth Valiant

255 messages,  Last post on May 30, 2009 at 8:37 AM

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Messages Page 22 of 26

#206 of 255 Re: car not charging [roozster] by texases

Dec 05, 2007 (1:00 pm)

Replying to: roozster (Dec 05, 2007 12:46 pm)
Only a few causes:
Battery - get a battery hydrometer and a charger (never hurts for an old classic car owner such as yourself to have a charger), unhook the cables, charge it up, test if there are any bad cells.
Alternator - how do you know it's good?
Regulator - Is it separate, or built into the alternator (I don't remember)
Connections - make sure they're all clean and tight.
 
Edit- where is the Alt. gauge pointing? And what are any other symptoms?

#207 of 255 Re: car not charging [roozster] by zaken1

Dec 05, 2007 (3:07 pm)

Replying to: roozster (Dec 05, 2007 12:46 pm)
As the other person suggested, it could be a variety of things. If the ammeter doesn't show a charge, then you probably have a defective voltage regulator. The regulator in that car is external, and is mounted on the firewall. The original regulator was mechanical, but there now are more reliable solid state replacements made by many manufacturers. There also may still be some mechanical regulators out there, so it is a good idea to check the type of the one you plan to buy.
 
If the ammeter does show a charge, but the battery keeps going dead, then you probably have a bad cell in the battery. You can confirm this by having the battery tested with a hydrometer and a load tester. Many auto parts stores will test batteries for free.
 
The battery also can go dead if an alternator diode is bad. There are 6 diodes in the alternator. If one of them goes bad, the alternator may pass a voltage output test, but it will not produce enough current to keep the battery charged at low engine speeds, or when headlights and other electrical accessories are in use. The only way to confirm this kind of problem is to test the alternator's current output.
 
A certain combination of bad diodes can also cause the battery to drain after the engine is shut off. If the battery has a charge in it, you can check for a battery drain by disconnecting the battery negative (ground) cable, and then touching it back to the post it was removed from. If there is a spark of any significant size, there is a drain. Of course, the lights must not be on, the doors and trunk must be closed, and the ignition key must be turned off. If you get a spark, disconnect the heavy cable at the alternator, and try the test again. If you now don't get a spark; you have bad alternator diodes.
 
There is also a fusible link in the positive battery cable. If that link goes open, the charging system will not work.

#208 of 255 There's an old saying... by andre1969

Dec 05, 2007 (4:09 pm)

with old Mopars. When in doubt, change the ballast resistor! It's like a 2-dollar part, mounted on the firewall, and looks kinda like this.
 
On my '68 and '69 Darts, it was mounted on the driver's side of the firewall, kinda high up. I think its main purpose is to cut down the voltage to the igntion coil so you don't fry the points, but it may cause other problems when it goes bad.

#209 of 255 Re: There's an old saying... [andre1969] by Mr_Shiftright HOST

Dec 06, 2007 (9:22 am)

Replying to: andre1969 (Dec 05, 2007 4:09 pm)
Good suggestion as a general rule but it probably wouldn't apply here. If the ballast resistor is bad, the car will start in the key's "crank" position but will stall the minute you release the key.
 
The owner could take the alternator off and Autozone will bench test it for you for free.
 
Or there's a way to by-pass the regulator but I'm not giving out electrical advice of this sort over the internet---I don't want somebody burning the garage down because my "green" wire has been changed to their "blue" wire.
 
A chilton's manual will tell you how to do the by-pass test (library book?)

#210 of 255 rear window rubber by roozster

Dec 06, 2007 (10:46 pm)

my dart didnt come with a back window and i have looked online for one but have realized they are pretty expensive.. amy info on where to get one in the san joaquin, California area.

#211 of 255 voltage regulator by roozster

Dec 10, 2007 (12:24 pm)

i need to replace my voltage regulator but i was told i have to be careful with polarity? never knew! what caution should i take or do before replacing .... thanx

#212 of 255 Re: voltage regulator [roozster] by texases

Dec 10, 2007 (12:26 pm)

Replying to: roozster (Dec 10, 2007 12:24 pm)
hmm...as long as you disconnect the battery before doing anything, and make sure all wires are connected to the proper posts, I don't know what the 'polarity' warning is all about. Is the new regulator identical to the old one?

#213 of 255 Re: rear window rubber [roozster] by roozster

Dec 10, 2007 (12:26 pm)

Replying to: roozster (Dec 06, 2007 10:46 pm)
or any i can order online

#214 of 255 Re: voltage regulator [roozster] by zaken1

Dec 10, 2007 (3:36 pm)

Replying to: roozster (Dec 10, 2007 12:24 pm)
It sounds like the person who told you to be careful with polarity meant that you should not exchange the wires to the regulator's two terminals. But one of those terminals is a quick disconnect tab; and the other one is a screw terminal. It would be impossible to exchange the wires to those terminals, unless someone modified the wiring harness, which is highly unlikely. I expect the person who gave you that advice was not familiar with this regulator. It almost sounds like he was talking about a regulator for an old DC generator.

#215 of 255 Re: voltage regulator [roozster] by zaken1 by roozster

Dec 11, 2007 (12:44 pm)

correct and another thing i found out is the regulator was mounted on the coil..

Messages Page 22 of 26

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