Notices
1978 - 1996 Big Bronco  
Sponsored by:
Sponsored by:

battery goes dead

Thread Tools
 
Search this Thread
 
Old Nov 22, 2004 | 12:53 AM
  #1  
Beastybroncothe2nd's Avatar
Beastybroncothe2nd
Thread Starter
|
New User
Joined: Oct 2004
Posts: 21
Likes: 0
battery goes dead

i have a new battery that dies when i leave the truck sittin for a couple weeks or so

could it be the dome light which is jammed on so i disconnected it?
or the radio which is frozen up?
 
Reply
Old Nov 22, 2004 | 01:38 AM
  #2  
justshootme84's Avatar
justshootme84
Posting Guru
Joined: Jan 2003
Posts: 1,388
Likes: 0
From: SE Texas
Try disconnecting the battery next time you let it sit for several days. Reconnect it and if it starts up fine, then you know for sure there is a current draw on the system. Most likely the dome light circuit, since the radio only comes on with the ignition key on. Check the charge before you start it and after running for a while, too. That will tell you if the alternator is charging, or you can unhook the positive cable while running (on non-computer motors ONLY). If the motor dies, the alt is bad.
 
Reply
Old Nov 22, 2004 | 02:16 AM
  #3  
aurgathor's Avatar
aurgathor
Cargo Master
Joined: Aug 2004
Posts: 2,899
Likes: 2
From: Lynnwood, WA
Remove the bulb from the dome light, or install a cutoff switch, because that's more than enough to drain (and eventually render useless) the battery. I had a similar thing when once I left the glovebox opened (had a light in) and not only the battery was completely dead after 2 months, but it wouldn't take charge very well any more.
 
Reply
Old Nov 22, 2004 | 07:33 AM
  #4  
spdjunke's Avatar
spdjunke
Junior User
Joined: Sep 2003
Posts: 90
Likes: 0
Beasty,

Do you have an aftermarket radio in it? Sometimes people miswire them, allowing the display to stay on when the key is not in the ignition.....if so, that would definately drain your battery.

The other suggestions are good starters as well, check the easy things first ( glove box light, dome light, underhood light ) and simply yank the bulbs out of them, let is sit for a week or so and see if it helps.
 
Reply
Old Nov 22, 2004 | 08:24 AM
  #5  
tom2131968's Avatar
tom2131968
Senior User
Joined: May 2003
Posts: 254
Likes: 0
The tried and true way is to put an amp meter in series with the battery and see if there is ANY current draw then start pulling fuses one at a time until you see the amount of draw change. At that point, you've isolated the circuit. How old is the battery?

Tom T
 
Reply
Old Nov 22, 2004 | 09:17 PM
  #6  
Beastybroncothe2nd's Avatar
Beastybroncothe2nd
Thread Starter
|
New User
Joined: Oct 2004
Posts: 21
Likes: 0
the battery is only like 3 months old, and it is definately not the alternater
the dome light is unscrewed enough to where it doesnt light up and the face plate to the radio is off of it but i was wondering if even then it could still draw it down or something associated with them that is not visable

sorry but i will be outa touch for a few days, i'll see what i can find though
 
Reply
Old Nov 23, 2004 | 12:11 AM
  #7  
aurgathor's Avatar
aurgathor
Cargo Master
Joined: Aug 2004
Posts: 2,899
Likes: 2
From: Lynnwood, WA
Originally Posted by tom2131968
see if there is ANY current draw then start pulling fuses one at a time until you see the amount of draw change. At that point, you've isolated the circuit. T
This is correct on older vehicles, but newer vehicles will draw some current (I measured, I believe 10 mA or so on my '95 Bronco) . Pulling fuses is somewhat pointless if the current draw is under some limit -- like 10 - 20 mA since it will reset the clock and the computer, and at the end one will conclude that the clock and the computer are drawing some current....
 
Reply
Old Nov 23, 2004 | 12:15 AM
  #8  
tom2131968's Avatar
tom2131968
Senior User
Joined: May 2003
Posts: 254
Likes: 0
You are correct, I forgot to mention that. But he will be able to isolate the draw on his system, because it will greatly exceed 10ma if it is killing the battery every week.

Tom T
 
Reply
FTE Stories

Ford Trucks for Ford Truck Enthusiasts

story-0

Top 10 Ford Truck Tragedies

 Joe Kucinski
story-1

AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make

 Brett Foote
story-2

Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!

 Michael S. Palmer
story-3

Ford's 2001 Explorer Sportsman Concept Looks For a New Home

 Verdad Gallardo
story-4

10 Best Ford Truck Engines We Miss the Most!

 Joe Kucinski
story-5

2026 Shelby F-150 Off-Road: Better Than a Raptor R?

 Brett Foote
story-6

2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!

 Michael S. Palmer
story-7

10 Most Surprising 2026 Ford Truck Features!

 Joe Kucinski
story-8

Top 10 Ford Trucks Coming to Mecum Indy 2026

 Brett Foote
story-9

5 Best / 5 Worst Ford Truck Wheels of All Time

 Joe Kucinski
Old Nov 23, 2004 | 08:05 AM
  #9  
Redbob's Avatar
Redbob
Senior User
Joined: Oct 2001
Posts: 268
Likes: 0
From: North Texas
[QUOTE=Beastybroncothe2nd]i have a new battery that dies when i leave the truck sittin for a couple weeks or so
QUOTE]

Sorta depends on how long the "or so" period is: if it turns out the battery is getting low after 4 - 6 weeks, well that's pretty normal and could easily be caused by no more drain than a clock or an onboard computer.
I've got an old pickup I only drive once every month or so, and to stop its battery from going dead I finally installed a battery cutoff switch for around $20. Of course you have to reset your radio every time you start up, but at least you start up!

- R
 
Reply
Old Nov 23, 2004 | 01:12 PM
  #10  
ruthless69's Avatar
ruthless69
Junior User
Joined: Sep 2004
Posts: 60
Likes: 0
From: CA
alternator

I had the same thing happen to me, took all the steps you are taking using process of elimination.

I finally took it to a local Electrical shop where they found it was my alternator.

I was hoping that was not the case since it can be expensive, but that seemed to be the problem and have had no battery problems since. Good luck.
 
Reply
Old Nov 24, 2004 | 09:04 PM
  #11  
Beastybroncothe2nd's Avatar
Beastybroncothe2nd
Thread Starter
|
New User
Joined: Oct 2004
Posts: 21
Likes: 0
Sorta depends on how long the "or so" period is: if it turns out the battery is getting low after 4 - 6 weeks, well that's pretty normal and could easily be caused by no more drain than a clock or an onboard computer.

it has been between 2 and 3 weeks
im pretty sure the alternater is the ok because after i do get it running it charges up fine and will crank up for a couple of weeks but if i dont run it again it looses the power
 
Reply
Old Nov 24, 2004 | 09:06 PM
  #12  
Beastybroncothe2nd's Avatar
Beastybroncothe2nd
Thread Starter
|
New User
Joined: Oct 2004
Posts: 21
Likes: 0
oh, and redbob thats a good idea but if i cant figure out whats drawing power i will prolly just pull off my battery cable when i will be leaving it sittin
 
Reply
Old Nov 25, 2004 | 12:57 PM
  #13  
Marquis's Avatar
Marquis
New User
Joined: Jan 2004
Posts: 11
Likes: 0
From: Jim Thorpe
The voltage reg. could be bad and causes the battery to die when sitting, sometimes overnight. The regulator is in the alternator so it requires replacement. Pulling a battery cable while the engine is running will cause the engine to die and does not indicate a bad alternator. The reason is, alternators have no iron core in their field windings to hold residual magnetism and rely on current flow from the battery to the field windings produce current. When you disconnect the battery, current flow thru the field windings stops and current production stops, resulting in the engine stopping.
 
Reply
Old Nov 29, 2004 | 12:56 AM
  #14  
aurgathor's Avatar
aurgathor
Cargo Master
Joined: Aug 2004
Posts: 2,899
Likes: 2
From: Lynnwood, WA
I was working on my girlfriend's Toyota today (battery dies after several days) and I measured 200 - 250 mA current draw on the battery when everything was OFF. You should measure the current draw, or ask someone to do it for you.
 
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
teppler
6.0L Power Stroke Diesel
10
Aug 19, 2020 09:55 PM
Milwaukee1979F150
1999 - 2003 7.3L Power Stroke Diesel
12
Dec 12, 2011 03:36 PM
quiacato
1999 - 2003 7.3L Power Stroke Diesel
6
Mar 8, 2011 10:16 PM
PAVEMENTMAN
1994.5 - 1997 7.3L Power Stroke Diesel
14
Dec 25, 2009 07:54 PM
kidoo
Pre-Power Stroke Diesel (7.3L IDI & 6.9L)
8
Mar 6, 2006 04:57 PM




All times are GMT -5. The time now is 01:48 AM.

story-0
Top 10 Ford Truck Tragedies

Slideshow: Top 10 Ford truck tragedies.

By Joe Kucinski | 2026-05-18 19:34:33


VIEW MORE
story-1
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make

And it might be even better than that.

By Brett Foote | 2026-05-18 19:26:42


VIEW MORE
story-2
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!

Slideshow: Does lowering an F-150 Lobo RUIN the ride quality?

By Michael S. Palmer | 2026-05-18 19:20:37


VIEW MORE
story-3
Ford's 2001 Explorer Sportsman Concept Looks For a New Home

Slideshow: Ford's bizarre fishing-themed Explorer concept has resurfaced after spending decades largely forgotten.

By Verdad Gallardo | 2026-05-12 18:07:46


VIEW MORE
story-4
10 Best Ford Truck Engines We Miss the Most!

Slideshow: The 10 best Ford truck engines we miss the most.

By Joe Kucinski | 2026-05-12 13:09:47


VIEW MORE
story-5
2026 Shelby F-150 Off-Road: Better Than a Raptor R?

Slideshow: first look at the 810 hp 2026 Shelby F-150 Off-Road!

By Brett Foote | 2026-05-12 12:50:07


VIEW MORE
story-6
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!

Slideshow: Everything You Need to Know about the 2027 Super Duty Carhartt Package!

By Michael S. Palmer | 2026-05-07 17:51:06


VIEW MORE
story-7
10 Most Surprising 2026 Ford Truck Features!

Slideshow: 10 most surprising Ford truck options/features in 2026.

By Joe Kucinski | 2026-05-05 11:17:22


VIEW MORE
story-8
Top 10 Ford Trucks Coming to Mecum Indy 2026

Slideshow: Here are the top 10 Fords coming to Mecum Indy 2026.

By Brett Foote | 2026-05-04 13:49:49


VIEW MORE
story-9
5 Best / 5 Worst Ford Truck Wheels of All Time

Slideshow: The 5 best and 5 worst Ford truck wheels of all time

By Joe Kucinski | 2026-04-29 16:49:01


VIEW MORE