battery drain help -

Go Back > Ford Mustang Tech > 4.6L (1996-2004 Modular) Mustang

4.6L (1996-2004 Modular) Mustang Technical discussions on 1996-2004 4.6 Liter Modular Motors (2V and 4V) within.

battery drain help

Thread Tools Search this Thread
Old 12-28-2009, 09:36 PM   #1
1st Gear Member
Join Date: Mar 2005
Location: VA
Posts: 74
Default battery drain help

i have a battery drain in a 2000 gt vert. I narrowed it down to the radio fuse 27. i guess that one is for the mach system? does anyone have a wiring diagram for that fuse only or know where i can get one?
smokinv6 is offline   Reply With Quote
Old 12-28-2009, 09:42 PM   #2
4th Gear Member
0949er's Avatar
Join Date: Mar 2009
Vehicle: 2004 Mustang GT
Location: NC
Posts: 1,909

Click the image to open in full size.

Hope that helps.

Vortech V1 T-Trim @ 7 PSI (tuned down)
Comp Cam Stage 2's (XE 270AH)
+ more (See Garage)

432 wrhp / 397 wrtq NOT FAST ENOUGH!!!
**It takes ~$60 a rwhp (over stock) for a 99-04 Mustang GT.** Do the Math
0949er is offline   Reply With Quote
Old 12-28-2009, 10:08 PM   #3
1st Gear Member
Join Date: Mar 2005
Location: VA
Posts: 74

i have that from the owners manual but i was wondering if there was anything out there that showed exactly what was on that circuit
smokinv6 is offline   Reply With Quote
Old 12-28-2009, 10:29 PM   #4
2nd Gear Member
Rokgtar's Avatar
Join Date: Apr 2008
Vehicle: 1997 Mustang Cobra (gone)
Location: Virginia
Posts: 379

I had a constant drain on my battery and it turned out to be one of the amps for my Mach 460 stereo... Pulled the fuse to the amps and the car sat cold for weeks and still kept a charge. It's not my daily driver so I have not replaced the amp(s) yet...
Rokgtar is offline   Reply With Quote
Old 12-28-2009, 10:29 PM   #5
2nd Gear Member
StripeyGT's Avatar
Join Date: Mar 2009
Vehicle: 2008 Hyundai Tiburon SE
Location: CA
Posts: 297

Check this link out. It has some schematics and quite a bit of info on our sound systems. Hope it helps.
2nd Corinthians 5: 17
StripeyGT is offline   Reply With Quote
Old 08-17-2012, 02:29 PM   #6
Join Date: Aug 2012
Vehicle: 2001 V6 Mustang Conv.
Location: Ontario
Posts: 1

Hi all,

Having the same issue 120 mHa draw on this circuit controled by fuse 27 Radio.

I disconnected the radio, the 2 amps in the back and still getting a drain. Is there anything else to discinnect on that circuit. ????

Took a full day to figure this out as i was unaware the GEM stays on for an hour of last activity. GEM is fine and does go to sleep, but the radio circtut still draws 120 mHa.
godman is offline   Reply With Quote
Old 08-17-2012, 08:56 PM   #7
cliffyk's Avatar
Join Date: Dec 2006
Vehicle: 1998 SL500
Location: Saint Augustine, FL
Posts: 10,924

Old thread, but great that you used the search function. Fuse 2.27 (25A) feeds nothing but the radio head unit and sub-woofer amps if you have them--however...

Here is the "dark-current" procedure from the 2001 shop manual, steps 4, 5 and 6 are very important or you will not get a proper reading.

NOTE: To accurately test the drain on a battery, an in-line digital ammeter must be used. Use of a test lamp or voltmeter is not an accurate method due to the number of electronic modules.
  1. Make sure the junction box/fuse panels are accessible without turning on interior and underhood lights.

  2. Drive the vehicle at least five minutes and over 48 km/h (30 mph) to turn on and exercise vehicle systems.

  3. Allow the vehicle to sit with the key off for at least 40 minutes to allow modules to time out/power down.

  4. Connect a fused jumper wire between the negative battery cable and the negative battery post to prevent modules from resetting and to catch capacitive drains.

  5. Disconnect the negative battery cable from the post without breaking the connection of the jumper wire.

    NOTE: It is very important that continuity is not broken between the battery and the negative battery cable when connecting the meter. If this happens, the entire procedure must be repeated.

  6. Connect the tester between the negative battery cable and the post. The meter must be capable of reading milliamps and should have a 10 amp capability.

    NOTE: If the meter settings need to be switched or the test leads need to be moved to another jack, the jumper wire must be reinstalled to avoid breaking continuity.

  7. Remove the jumper wire.

    NOTE: Amperage draw will vary from vehicle to vehicle depending on the equipment package. Compare to a comparable vehicle for reference.

    NOTE: No production vehicle should have more than a 50 mA (0.050 amp) draw.

  8. If the draw is found to be excessive, pull fuses from the battery/central junction box one at a time and note the current drop. Do not reinstall the fuses until you are finished testing.

  9. Check the wiring schematic in the wiring diagram for any circuits that run from the battery without passing through the battery/central junction box. Disconnect these circuits if the draw is still excessive.
-cliff knight-
SOLD! - 2003 GT, UPR X, FRPP 24lb/h, Magnaflow, PP 70mm TB & plenum,
Delta Force tuned, Steeda UDPs, Ralco flywheel,
RAM HDX clutch, 3.73s, 262 rwHP/305 lb-ft.

New ride (7/1/2013) 1998 Mercedes SL500-5.0L 32V VVT 326/347 HP/tq

Engineering is, at its base, making what you want from what you have.
At its extreme it is making what you want from what you can get.
cliffyk is offline   Reply With Quote


Similar Threads
Thread Thread Starter Forum Replies Last Post
2014 convertible water drains jerrytubes 2005-2014 Mustangs 2 10-23-2015 01:11 PM
Rough idle and vibrating 4cylinderplus2 V6 (1994-2004) Mustangs 9 09-30-2015 06:26 PM
Clear codes on '94 sn95 BOB ROME 5.0L (1979-1995) Mustang 2 09-28-2015 12:10 PM
Need to rebuild the automatic transmission 1996 GT wraith777 General Tech 1 09-28-2015 11:49 AM
seems like car doesn't have enough juice to turn over logan409 4.6L (1996-2004 Modular) Mustang 10 09-26-2015 08:43 PM

2007, 50, 50mustang, acceptable, baterry, battery, body, drain, draining, fast, fox, mach, mustang, problem, radio

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Forum Jump


All times are GMT -5. The time now is 12:48 AM.

This forum is owned and operated by Internet Brands, Inc., a Delaware corporation. It is not authorized or endorsed by the Ford Motor Company and is not affiliated with the Ford Motor Company or its related companies in any way. FordŽ is a registered trademark of the Ford Motor Company