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Old 01-02-2014, 12:00 AM   #1
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battery draw help!

So recently got the car (my 66) up and running again, but the battery died overnight, so I charged it and hooked it up to a multimeter in series and I have a 3.2amp draw. Took the fuse box downand pulled each fuse 1 by 1 and nothing changed with my draw. Took the radio fuse out and still have a draw. Any thoughts on where it might be coming from. A/c? Possibly the starting solenoid. The alternator seems to change the battery as once I get it running the load is in the normal range. What am I missing? Thanks all!
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Old 01-02-2014, 12:12 AM   #2
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The diodes in your alternator are probably bad.
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Old 01-02-2014, 12:24 AM   #3
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if thats the case wouldnt it keep the alternator from charging the battery? Just curious
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Old 01-02-2014, 12:38 AM   #4
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Not necessarily. It can still charge with bad diodes.
Charge the battery then hook everything up and wait until nighttime. Go feel the alternator when everything is cold. If the alternator is warmer than everything else in the engine bay, you've found your problem...
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Old 01-02-2014, 05:20 AM   #5
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Check your voltage regulator.

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Old 01-02-2014, 07:33 AM   #6
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Not sure how easy it will be but leave the DVM in series (like you did before to see the current draw) unplug each cable going though the Firewall and see if any of them stop the draw, if one of them do chase the wires and see where the short is. If not move out to the engine compartment and do the same thing. I really sounds like a shorted wire someplace. They are a pain to troubleshoot.
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Old 01-02-2014, 10:01 AM   #7
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Thanks guys I will try all this it is all very helpful!
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Old 01-06-2014, 09:07 PM   #8
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Alright, so today I disconnected the voltage regulator, and ran it in series again and the amp draw went from 3.2amps to 0.03. So I think I've isolated the majority of the problem....I think. Should I worry about the remaining 300 miliamp draw? or would that be considered acceptable?
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Old 01-06-2014, 10:37 PM   #9
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Quote:
Originally Posted by Benzopyrene View Post
Alright, so today I disconnected the voltage regulator, and ran it in series again and the amp draw went from 3.2amps to 0.03. So I think I've isolated the majority of the problem....I think. Should I worry about the remaining 300 miliamp draw? or would that be considered acceptable?

Don't quote my math, but I think 300 mA is the current a 4 or 5 W bulb would draw at 12V. Not sure if this is a product of measuring or how long you could sustain that draw...either way a huge improvement, good work!

---------- Post added at 10:37 PM ---------- Previous post was at 10:36 PM ----------

Wait, 0.03 A is only 30 mA...
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Old 01-07-2014, 07:34 AM   #10
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Quote:
Originally Posted by Benzopyrene View Post
Alright, so today I disconnected the voltage regulator, and ran it in series again and the amp draw went from 3.2amps to 0.03. So I think I've isolated the majority of the problem....I think. Should I worry about the remaining 300 miliamp draw? or would that be considered acceptable?
Before I answer this I have a few questions

You disconnected the voltage reg with the car shut off?
if you did and the draw dropped to 30ma then I say you have to test the alternator also before you call the VR bad

If the car was running and you did this I am not sure what is going on.

To answer the last question 30ma is not a bad draw whit nothing on.. Depending on what type radio you have in it.
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Old 01-08-2014, 10:25 PM   #11
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The series testing was done with the car off. I also did the test from the video above, and car stays on when the battery is disconnected, and also stays on when it is disconnected with the voltage regulator disconnected and a paper clip in to loop the circuit. So according thO the video that would isolate the voltage regulator as well. Does anybody recommend a specific vr? Motor craft or will any auto part store version do as they seem to be in stock everywhere and pretty cheap.... Except the motor craft one of course. Cheers! Thanks for all the help guys!
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Old 01-08-2014, 10:29 PM   #12
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Never done it myself, but I've heard that the newer solid state ones are the way to go, not the expensive replicas. If you want the stock look, it's pretty easy to drill out the rivets and switch the cover over if that's a concern.
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