Notices
1999 - 2003 7.3L Power Stroke Diesel  
Sponsored by:
Sponsored by: DP Tuner

Battery drain

Thread Tools
 
Search this Thread
 
Old Nov 25, 2015 | 01:37 PM
  #1  
AndysFords's Avatar
AndysFords
Thread Starter
|
Laughing Gas
Joined: Mar 2006
Posts: 1,083
Likes: 1
From: Fitzpatrick Alabama
Battery drain

I have a slight drain on my 2000 f250. Appears to be related to fuse 15 which is pcm/gem module. How do I go about finding it from here now that I know it's that fuse.
 
Reply
Old Nov 25, 2015 | 03:35 PM
  #2  
thomabb's Avatar
thomabb
Cargo Master
15 Year Member
Joined: Apr 2010
Posts: 2,405
Likes: 4
How much is the drain? The PCM will draw a small amount of current when the truck is off to keep it alive.
 
Reply
Old Nov 27, 2015 | 01:20 PM
  #3  
AndysFords's Avatar
AndysFords
Thread Starter
|
Laughing Gas
Joined: Mar 2006
Posts: 1,083
Likes: 1
From: Fitzpatrick Alabama
Originally Posted by thomabb
How much is the drain? The PCM will draw a small amount of current when the truck is off to keep it alive.
It's killing my battery overnight. Not completely but enough it won't start the next morning. I noticed last night when I went to get in the truck the back light on the radio was lit up real dim.
 
Reply
Old Nov 27, 2015 | 06:39 PM
  #4  
thomabb's Avatar
thomabb
Cargo Master
15 Year Member
Joined: Apr 2010
Posts: 2,405
Likes: 4
Have you measured the draw? Do you have a meter?
 
Reply
Old Nov 29, 2015 | 08:46 AM
  #5  
AndysFords's Avatar
AndysFords
Thread Starter
|
Laughing Gas
Joined: Mar 2006
Posts: 1,083
Likes: 1
From: Fitzpatrick Alabama
I have a volt meter I don't know what kind of meter you mean
 
Reply
Old Nov 29, 2015 | 09:04 AM
  #6  
Tedster9's Avatar
Tedster9
Post Fiend
Joined: Apr 2002
Posts: 19,311
Likes: 97
From: Waterloo, Iowa
If it's dead overnight we already know the draw is excessive. Trick is to find it. Is the radio or stereo aftermarket? First thing is disconnect anything that isn't factory. Also get battery on charger asap.

(To check for actual current draw set DMM for amperes and install in series with positive or negative cable and battery.)

It can take a half hour or so for all the modules to power down and accurately measure the true resting current draw. Should be approx. 50 milli-amperes or less. Can start pulling fuses individually to see what's what. Alternatively pull all the fuses and reinstall to isolate the problem circuit.
 
Reply
Old Nov 30, 2015 | 07:51 AM
  #7  
thomabb's Avatar
thomabb
Cargo Master
15 Year Member
Joined: Apr 2010
Posts: 2,405
Likes: 4
Your comment about the radio backlight - I also can see a small light that stays on inside the radio. As long as your draw is less than 1 mA you should be OK.


With the information you have given so far, there are a couple things to check. The mA draw after about an hour down (like Tedster9 says) if you can. Check the voltage at the batteries with the truck running and off. You should see about 14v with the truck running and somewhere between 12-13v with the truck off. Voltage checks should be very close if not the same at each battery. This will tell you if you should be looking at batteries or alternator.
 
Reply
Old Nov 30, 2015 | 07:56 AM
  #8  
thomabb's Avatar
thomabb
Cargo Master
15 Year Member
Joined: Apr 2010
Posts: 2,405
Likes: 4
Have you ever noticed moisture under the dash by your left foot?
 
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 30, 2015 | 09:09 AM
  #9  
GEugeneS's Avatar
GEugeneS
Laughing Gas
20 Year Member
Joined: Mar 2004
Posts: 789
Likes: 16
From: West Coast/L.A. Area
I've had my 7.3 since 2007. In that time I have had 2 batteries (an AutoZone and a Costco) short out on me giving out only about 10.3 volts. Found out later both companies use Interstate for their batteries. In any case, I assumed that there was some kind of battery drain going on because the voltage would appear normal after I drove it a bit, but the next morning the truck would barely start. This was of course because the shorted battery was pulling the other battery down. I would say charge the batteries, disconnect them and check the voltage the following morning. If one is really low, it's probably shorted out internally.
 
Reply
Old Nov 30, 2015 | 12:15 PM
  #10  
GEugeneS's Avatar
GEugeneS
Laughing Gas
20 Year Member
Joined: Mar 2004
Posts: 789
Likes: 16
From: West Coast/L.A. Area
btw, just disconnecting the battery grounds should do it. also you will lose your preset radio stations and the PCM will have a bit of learning to do.
 
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
strobewylan
1968-Present E-Series Van/Cutaway/Chassis
0
Apr 16, 2017 09:54 PM
Lincoln White
1997 - 2006 Expedition & Navigator
22
Mar 3, 2017 07:27 AM
vjsimone
6.4L Power Stroke Diesel
2
Jun 16, 2013 01:41 PM
Mike in Ohio
1967 - 1972 F-100 & Larger F-Series Trucks
4
Feb 29, 2012 06:50 PM
johnanderson
Electrical Systems/Wiring
2
Jan 6, 2004 03:43 PM




All times are GMT -5. The time now is 08:24 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