drain on battery??
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Freshman User
Joined: Sep 2010
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From: mo.
drain on battery??
I have something draining the battry. i have disconnected the battery neg post and hooked up my test lite. pulled every fuse one at a time and never did get the lt. to go off. whats next. thanks
Laughing Gas
Joined: Feb 2011
Posts: 1,147
Likes: 6
From: Vine Grove KY
Start unplugging accessories like the radio, one at a time and re-testing. Try to isolate as many circuits as possible and write down each circuit on a paper as "good" until you find the faulty one. There was a recent thread on here with another FTE member who was having a similar problem, you might try reading that thread. I will see if I can find it for you.
Laughing Gas
Joined: Feb 2011
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From: Vine Grove KY
Elder User
Joined: Jul 2012
Posts: 553
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From: Raleigh, NC
Maybe some inline fuses for added accessories? You don't say how long it takes to discharge. Audio systems with remote control draw a little current unless they're turned completely off.
If you have a volt/ohm/amp meter with 10 or so amp capacity, you could measure the amp draw between the disconnected battery cable and the battery post. Might blow a fuse in the amp meter if the draw is above the meter capacity.
Does the test light go out if you disconnect the voltage regulator?
If you have a volt/ohm/amp meter with 10 or so amp capacity, you could measure the amp draw between the disconnected battery cable and the battery post. Might blow a fuse in the amp meter if the draw is above the meter capacity.
Does the test light go out if you disconnect the voltage regulator?
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Freshman User
Joined: Sep 2010
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From: mo.
Ya i think i read that one was trying it without the amp metet just using the test lite. thougjt it would work. but every fuse i pull the lt. stays on which tells me it might be a combination of 2 or 3 things which will be a pita to figger out. hey thanks though.
Lead Driver
Joined: Jul 2009
Posts: 6,477
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From: Sheffield, AL
Defective alternators are known to drain a battery. With the battery already disconnected, disconnect the electrical connection to the alternator and then test for electrical draw at the battery, as you have already done.
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Laughing Gas
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Freshman User
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From: mo.
ok lets review
1985 f150 4x4 351w 4bl. 3spd auto. battery drains in less than 2 hrs. truck runs awesome. i checked evety fuse light stays on. i unhooked the alt. stays on . sounds like i may need a meter instead of the lt. if it is a combination of 2 or 3 things it may be easier to detect with a meter does this spund right?? thank you
Elder User
Joined: Jul 2012
Posts: 553
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From: Raleigh, NC
If battery drains in 2 hours, you either have a bad battery or a big drain. No need to measure the current. If its draining a good battery in two hours you might look for something that's hot to the touch.
I'd still be looking for a single problem, e.g. alternator or regulator.
I'd still be looking for a single problem, e.g. alternator or regulator.
Moderator
Joined: Nov 2007
Posts: 22,415
Likes: 92
From: Denver Metro Area, CO
Remove the alternator and have it tested at a parts store.
I agree with Mav.... if it drains in 2 hours, either the battery is defective or something in the electrical or wiring will be smoldering....
I agree with Mav.... if it drains in 2 hours, either the battery is defective or something in the electrical or wiring will be smoldering....
Laughing Gas
Joined: Apr 2013
Posts: 1,047
Likes: 63
FWIW, on my '86 E350 I had a bad starter relay that caused my fuel pump to run all the time (even with the key off). Took me a while to figure that one out.
The draw killed my battery pretty quick.
Do you have an electric fuel pump and can you hear it running all the time?
The draw killed my battery pretty quick.
Do you have an electric fuel pump and can you hear it running all the time?
Postmaster
Joined: Feb 2011
Posts: 3,560
Likes: 1
when i face these issues, i always start at the starter solenoid, pull off all the fusible links from the hot side of the solenoid, leaving only the battery wire on, place a test light between the battery ground and its ground cable, then start adding one fusible link at a time until i find the one that lights the tester. its usually either a bad alternator, or some aftermarket accessory thats doing it.
remember, all power flows through that point unless something aftermarket has been wired straight to the battery, so thats guaranteed to start you toward isolating the problem.
remember, all power flows through that point unless something aftermarket has been wired straight to the battery, so thats guaranteed to start you toward isolating the problem.
Cargo Master
Joined: Apr 2010
Posts: 2,936
Likes: 9
From: Acworth, GA
I have some helpful troubleshooting information here; Ford Truck Enthusiasts Forums - Grubbworm's Album: Troubleshooting help, for anyone that needs it.
And here; Ford Truck Enthusiasts Forums - Grubbworm's Album: Troubleshooting help, for anyone that needs it.
And here; Ford Truck Enthusiasts Forums - Grubbworm's Album: Troubleshooting help, for anyone that needs it.