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Old 05-30-2019, 04:09 PM   #1
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Default Need electrical help

I am new to working on my A , when I got it out for the driving season the generator was not charging. I replaced it and now my ameter wildly bounces from discharge to charge and the junction box on the firewall gets really hot.
What have I done wrong? It is probably something easy , but with my limited experience I am stumped.
Thanks for any help you can provide.
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Old 05-30-2019, 04:51 PM   #2
BRENT in 10-uh-C
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Default Re: Need electrical help

My first instinct is there is a loose connection somewhere or a wire that is intermittently shorting. What Cut-out are you using?? Do you have the correct polarity???
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Old 05-30-2019, 05:34 PM   #3
jrelliott
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Default Re: Need electrical help

If you have an newer junction box, some of them had problems with the screws shorting on the back. Pull the box and look at the box. Remember to disconnect battery before working on electrical things. The smoke gremlin is always lurking if you are not careful.
Make checks with an ohm meter to be sure no shorts, before reconnecting the battery.
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Old 05-30-2019, 06:34 PM   #4
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Default Re: Need electrical help

Does your alternator have only one wire connected to it ? If so ,then it is important that your alternator is grounded against the engine block,Sometmes the mounting bolts are insufficient to create a good ground and you will have a flickering amp.I added an extra wire from the alternator to the block which solved the problem.vic
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Old 05-30-2019, 06:49 PM   #5
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Default Re: Need electrical help

What is the polarity of your car? It was originally positive ground: is it now?
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Old 05-30-2019, 10:35 PM   #6
larrys40
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Default Re: Need electrical help

Quote:
Originally Posted by BRENT in 10-uh-C View Post
My first instinct is there is a loose connection somewhere or a wire that is intermittently shorting. What Cut-out are you using?? Do you have the correct polarity???



I agree with Brent on the intermittent short. A problem area that is very common is the reproduction terminal boxes. I always say they come with a potential built in short because the studs (unlike original units) are threaded machine screws that are not fully tightened to the nuts on the front side. If the connection gets poor the stud can heat up with the plastic box and melt and then the screw head is right there at the firewall to short. First thing I do when checking terminal boxes is if the terminal stud wiggles at all it is loose and the potention problem is there.

To correct remove the box and check box for any previous overheat. If occured throw away and put on good original or repro if necessary. Prior to using the repor tighten screw studs tightly and then use 5 minute epoxy to fill screw holes over screw heads. once dry mount to firewall and wire as normal.
I see this all the time so it is very common. Loose ammeter studs are the same... its really about tight connections everywhere.

Hopefully you'll find the culprit. If you know how to use a voltmeter do so.. lower voltages from source (battery) voltage ( tenth or otherwise) indicate resistance which is generally poor connections.

It's the electrically shocking truth!
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Old 06-02-2019, 07:56 AM   #7
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Default Re: Need electrical help

It is still positive ground , 6 volt
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