I have a 68 D100 with a slant. The truck started acting up by not starting, needing a jump start. Battery would not last long after being on charger, so I replaced it. Truck runs great, but when I disconnect one of the terminals from the battery, the truck dies. I tried the alternator out of my dart, same thing. I replaced the voltage regulator, no difference. What should I be checking?

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Excuse me, does this smell like chloroform to you?

The wiring from ignition switch to voltage regulator, from regulator to alternator field, and from alternator output to the truck's main feed circuit.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Here's a wiring diagram.

http://www.sweptline.com/tech/68wire.jpg

Danny

It is never a good idea to disconnect the battery from a running vehicle. If the alternater is good , it can go to full output (voltage) and burn out electrical things. On our early cars, usually just bulbs, or radio. On a newer computer car Very expensive components. Everyone who works on thier own cars, shoud have a multimeter. Can be bought cheep at Harbor Freight, Radio Shack, etc. Then you can check the battery voltage, with the engine off, and see if it is higher with the engine running. That will tell you the same thing as disconnecting the battery. That the Alt is putting out something, but not whether it is putting out enough. That will require addtional tests, which can only be done with the meter.

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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

Well I cleaned the electrical contacts from the battery, alternator, regulator, solenoid on the fender, and the posts on the back of the voltmeter. The voltmeter does move, dips slightly into the discharge side, then VERY slowly centers itself. I also noticed that I get a shock quite often when exiting the truck. Part of the Puzzle?

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Excuse me, does this smell like chloroform to you?

I'd like to second NOT disconnecting the battery w/ the engine running - I've measured 50V out of a Mopar alt. Also, Harbor Freight is selling a cheap digital multimeter (DMM) for $2, so there's little excuse not to have one. Even a cheap DMM is very handy - I keep one in each of my cars' toolboxes, just in case.

Any shock exiting the truck probably is static; some tires are not sufficiently conductive to bleed off the charge. I don't easily see how the charging system could have anything to do with it.
T
he brushes for your alternator are inexpensive and easy to change from the outside; often, that's the cause of poor charging. There are 6 diodes inside the alt, and one or more can fail. You can't check them individually w/o opening up the alt. or using a scope. Also, Mopar regulators can partially and/or intermittantly fail; I had one that would only quit sometimes & only at highway speed. After 40 years, both all solid state & electromechanical regulators (like yours) are prone to problems.


Fortunately, replacement regulators are quite inexpensive. I bought one from J.C.Whitney a few years back for the TMC '65 Barracuda (http://www.tidewatermoparclub.com/Givea ... /2001.html)
for $10 or so - it was all surface mount electronics inside rather than relays, but it looked almost identical to the stock one (by having lots of empty space under the cover). If I'd wanted it to appear virtually indistiguisable from stock, I could have moved the old cover onto the new base.

Careful with cheap/no-name regulators...not worth the savings to wind up dead by the side of the road some dark night, in my opinion. Spend a little more money for a branded regulator.

See this post (and click/read the links from there) for test/repair info on your charging system. Should be fairly simple to get it up and charging again.

The static shock is not related to anything but the material your clothes are made of and the material the seats are upholstered with.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Thanks for the help guys. I will check the link posted and report back.

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Excuse me, does this smell like chloroform to you?

I checked what I could of the charging system. I took it in today. The alternator that I took out of my dart and installed in the truck was "transistorized", correct terminology? There are two spade connectors on the back of the alternator, for my truck, one needs to be grounded. I had left it untouched. Works fine now. Thanks for all your help.

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Excuse me, does this smell like chloroform to you?

The alternator is made to be used with the "transistorized" (electronic) regulator, hence the term. The only difference in the alternator is that both leads of the field are isolated from ground.

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Chuck Rivers, Webmaster