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1955 Ford
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I have a 1955 ford pickup that I bought about a year ago. I have been having problems with the battery draining. Every time I want to start it I have to put a charger on it. Once it starts it runs fine and doesnt cut off but if I shut it off within a few hours the battery goes dead and it wont start again without being charged. It has a brand new battery and alternator in it and I still have the same problem. The guy i bought it from put an updated fuse box in it and rewired the whole truck. I cant figure out what it is that is draining power off the battery when the truck is off. If anybody has any suggestions it would be a big help. Thank you.
 

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Is it modern electrical or old school? I'd start by making sure the alt 2 wire connector is sired correctly, if the wires are reversed, the sense wire is shorted to ground thru the voltage reg and will drain your batterty in a couple hours if the eng isn't running ect.... If this is the case the alt case wil get too hot to touch.
 

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Next time it is all charged up and you are done using it , pull all the fuses and see if it keeps the charge.
If it does then next time pull all the fuses but one and so on until it does not hold the charge. Then assume the problem is in the circuit that that fuse protects and trouble shoot from there.
I once had a similar problem on a brand new car and did this procedure. Traced it to a cigerate lighter that was falling apart and was grounding and draining the battery but not blowing the fuse !
 

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Run the truck, get the battery charged. Disconnect the negative battery cable. Now, pull all the fuses.
Do not hook up the negative cable, yet.
Take a common test light. Connect the test light to the negative battery post, and the disconnected negative terminal. If the light lights up, possibly a drain in the charging circuit, see if the key is off. Unplug the connections on the alternator, and check with the test light again. You may have to disconnect the main positive charging wire, if the alternator diodes are bad.

If the test light does not go on, with all the fuses out, put them in one by one, until you find the drain, with the test light between the negative battery post, and the cable.
 

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DanielC is correct although I would make one change to the last part of his procedure if possable. I'd use a multimeter instead of a test lamp. Multimeters are available for less than $20 nowadays and a multimeter on DC Amps would show you how much current is going through as you put each fuse in. Circuits like the ones for your digital radio, clock, interior light (you've probable got the door open), will all light up a test light but will give you a low amperage reading with a multimeter. See witch circuit gives the highest amp reading and correct from there.
Don
 

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The multimeter is a good tool to use, also. Just one caution. If you have a fairly high amp draw, it is pretty east to damage a multimeter on the amp setting, if there is a high amp draw.
Even with a dead short, a test light just shines it's normal brightness.
 
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