06 Mustang GT

Hi Guys, I know that the battery drain issue has been a big topic for us Mustang owners and I have been trying to diagnose my drain for the last few months and I'm hoping someone can help me solve this problem. My '06 Mustang GT is only driven a couple days a week but I do put it on the charger once a week as well. Up until a few months ago I have had no drain issues at all and then out of the blue my battery went dead within a few days, I charged it up and it was fine for another month or so but then it died again and continued to lose its charge ever since. I then replaced the battery figuring that it was due anyway but the new battery still was not holding a charge so I knew that I had a drain somewhere. The car only has 12,000 miles on it. I have the Shaker 500 sound system but I recently replace the headunit with a JVC touchscreen. The drain was occuring before I replaced the headunit and I disconnected the front amps as well as all of the stereo fuses for a day but the drain continued. The battery loses around .10 volts a day. I installed a battery disconnect switch on the negative battery cable and when I shut it down the battery holds a charge pefectly, but I don't want to have to reprogram my stereo as well as have the computer reset itself every day if I can avoid it. Today I pulled every fuse and relay one at a time from the engine bay fuse box and found that when I disconnected fuse# 67 (SJB# 4 Instument Panel Fuse Box) the battery voltage increased by about .05 volts, I then pulled each fuse one by one as well as the one relay from the Interior Fuse Box (SJB) on the passenger side kick panel but none of them changed the voltage at all! I don't know what else the fuse# 67 controls. So now I have no freakin' clue where this drain is coming from, so if anyone has any solutions I would love to hear them. Sorry for the long post but I wanted to give all of the information that I have. Thanks a lot guys, I really appreciate any help you can give me!
Dave

wayne613

While voltage is a good general indicator, can you not disconnect the main ground and use the multi-meter's ammeter functionality to isolate this beyond a doubt? If you have a decent one it should be good for 10amps. More than enough to diagnose a parasitic drain issue.

As for 67:
http://iihs.net/fsm/?dir=40&viewfile...%20Cluster.pdf (page 2)

AND
http://iihs.net/fsm/?dir=40&viewfile...bution-SJB.pdf (page 11, connector "J" is the feed for it from page 3).

Fuse 4 in the SJB is not connected to fuse 67 in the BEC. That(fuse 4 in SJB) is tied to BEC fuse 44.

Art161

Did you remove F8 and F10 from the SJB while F67 was connected?

I'm having trouble figuring out the wiring diagram, but since F67 controls the SJB, I think you need to leave F67 in while you troubleshoot the SJB. You need to get as close to the source of the problem as you can.

Good luck.

06 Mustang GT

Thanks a lot for the replies Wayne and Art. Wayne, I have just a basic Multi-meter and am not sure if it has an ammeter function or how to use the ammeter function if it does. And I have another stupid question, when you say the main ground are you refering to the neg. batt. cable or is there a ground strap connected to the engine and if so where is it that located? Also thank you very much for the wiring diagrams, I'm still trying to figure them out but they will be a big help.
And Art yes I did have the #67 fuse connected when I checked the fuses and relay in the SJB. Again, Thank you both for the replies, I really appreciate it!
Dave

wayne613

Likely going to want to splurge the bit extra for a decent digital multi-meter if that doesn't have it then. Should show a line with a max fuse rating between 2 of the test probe ports indicating max amperage it's capable of handling:

http://www.homedepot.com/h_d1/N-5yc1...&storeId=10051
One of the better Fluke models would be ideal, but expensive. Most of the knock-offs will do just as well in the $40-$80 range.

As for ground, either will likely do, but I would disconnect the negative terminal as shown in the video below, just to be sure it's not getting ground from the engine to the frame and fooling this test.
To measure(when you have a DMM capable of it), you run the test leads in series(in line between, meaning 1 test lead going to the battery, other to the ground/negative cable).
http://iihs.net/fsm/?dir=40&viewfile=Grounds.pdf
http://iihs.net/fsm/?dir=40&viewfile...on%20Views.pdf (page 3)

[youtube]zdIKNnwEjIs[/youtube]

wayne613

http://iihs.net/fsm/?dir=361&viewfil...g%20System.pdf (Page 15):
You will need to fool the door switches by holding them in with something, grounding the switch manually, or whatever while trying to test this, as shown in the generic video before. Ours are on the door itself if I recall correctly. Should be easy enough to find.
The SJB will kill the lights and such after a bit, but that's still giving another minor parasitic draw to the controller at best if it's forced to do the work for you.

Blacksmoke

Just a general thing to note:
I'm sure you know they have replaced the original alternaters in the 05-06's with different model alternaters numerous times.

They finally have one they stuck with.
Ours had to be switched to the new one when we had our 06GT.
We got a new stereo and it was your general run of the mill stereo swap, not a huge
bump in voltage use. And the next day we were drained.

06 Mustang GT

Thank you very much Wayne for all of the information that you gave me I really appreciate the time you took to help me out! I will be using the info to help diagnose my drain. And thank you Blacksmoke for your reply also! I'll let you guys know how I make out.

Blacksmoke

Hope all goes well my friend!
And def. let us know how it turns out!

caaraa

a great site,many useful information!