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Discussion Starter · #1 ·
Either way the result is the same: my '65 is suddenly taking the battery down.

I had installed a new master cylinder and was in the cab pumping the brakes when I noticed that my dome lamp went out everytime I pressed the brake pedal. Checking the battery I found it seriously discharged. After charging the battery up about 50% I got out my digital volt-ohm meter. On the continuity setting my VOM is giving audible buzzing from the main power lead (non-starter) off the battery.

I have a fair idea how to proceed and isolate circuits for draw/short testing. My questions are:
1) On a non electronic efi system with just the rudimentary electical are there common trouble spots?
2) Do one wire alternators have a little draw even when engine and all accesories are turned off?
3) What about the alternator diode trios and the horn relay?

Thomas
 

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Shoudn't be any draw off the battery with the car off. Exceptions are things like a clock or a memory circuit. An aftermarket radio can contain a memory for a clock and presets.
Disconnect the negative cable off the battery. Put a test light bulb between battery (-) and its cable. The light should not come on if you do not have one of the above items.
 

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One wire alternator will have small draw all the time. With out the "kicker" wire hooked up the alt. doesn't know when the car is turned on/off. That is why you have to "rev it up" a little on start up to get the alt going.
 

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Discussion Starter · #4 ·
Dennis, that is exactly what I came up with - the draw was indeed coming from the one wire alternator. Apparently it had been longer than I thought since I had seriously driven the car - maybe three weeks. I had started it up in the meantime one day while working on the ignition advance, but it hadn't seen any road time for at least three weeks.

Thomas
 
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