Parasitic drain - SJB issue

tirediron

New Member
May 24, 2020
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Hello everyone, new member here and seeking some assistance on a problem with a 2006 V6. About six months ago, it developed a parasitic drain (130 ma) which was killing the battery every few days. By process of elimination, I was able to trace the drain to the SJB (passenger foot well fuse panel), but no further.

First, before I was able to isolate the problem as the SJB, I had to take ALL the fuses out of the main, under hood fuse box. After some trial and error, I localized it to fuses 59 and 67 (which are two of the three feeds to the SJB), but the drain only stopped when BOTH fuses were removed. Further, even removing ALL of the fuses and the relay from the SJB had no effect on it; it was present as long as at least one of either fuse 59 or 67 were in place in the main fuse panel.

This leads me to believe that the problem is likely a fault with the SJB module itself since under normal circumstances removing one fuse from the main panel should have stopped the drain, and because the problem doesn't seem to go downstream from the SJB, but rather stops within it.

I've had a good look around and there are no obvious signs of water damage, but I haven't actually removed the SJB module from the car yet, so, questions:

1. Does my hypothesis of the fault being internal to the module make sense?

2. Is this a part which should be sourced only from OEM, or is after-market (if such a thing exists) or junkyard replacement reasonable?

3. Is this a plug & play module, or does it need some sort of initialization to work with the car? I read one article that indicated it came with factory set DTCs which had to be cleared in a specific sequence to "initialize" it.

Any other points, thoughts or words of wisdom much appreciated.
 
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cbxer55

Active Member
Jan 25, 2020
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Oklahoma
Sorry, no help here. But what does SJB even mean? But it does seem to me if you've localized the problem to the "SJB" and not downstream from it, that replacing it should fix it right up. But not knowing what a SJB even is, I have no idea if it's plug and play. Or whether it needs to be initialized like the ECM does (Flash).
 

tirediron

New Member
May 24, 2020
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Thanks for the reply. "SJB" is "Smart Junction Box" the official name for the passenger foot well fuse panel. Unfortunately, it does a lot more than just hold fuses which is why I'm looking for guidance.
 

cbxer55

Active Member
Jan 25, 2020
250
53
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59
Oklahoma
Well, hopefully someone that knows chimes in and get you the guidance you need. Done any searching of the forums to see if it's been brought up before? For instance, if you scroll to the bottom, other threads with similar titles appear. Maybe one of them will help you.

And there's a bunch btw. Hope I never have that problem. LMAO!
 

tirediron

New Member
May 24, 2020
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Searched all the forums and other on-line resources I can find, but as usual, you can never find another case with exactly your circumstances. I'm not a Mustang person, so I'm not really up on the details of this particular module. I'm about 95% confident in my diagnosis, but not sure about the replacement options.
 

cbxer55

Active Member
Jan 25, 2020
250
53
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59
Oklahoma
Yeah, I was never a Mustang person either, til this particular one caught my eye. There's just so many Stangs here, I never thought I'd own one. And then it happened. LOL!!
 

whisperer

New Member
Dec 25, 2000
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www.vintage-automotive.com
I'm also in a fight with my SJB so will be looking for information. If I find info that is not all over I will post it. I just replaced mine and went with a OEM Ford panel because these have multiple and frequent problems. I don't want to trade the problem on my car for one from another used unit. Just installed my new one and it did not fix the problem, yet.

I have not heard of the factory installed DTC thing. Interesting. I am under the impression that either Forscan software or the dealer MAY have to "activate" the box for the particular car. Jury's still out on mine.
 
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