Electrical Wows

Discussion in '2005+ Mustang GT 4.6L Tech' started by scramblr, Jul 27, 2021.

  1. 86GT351

    86GT351 forum member

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    THis is per Ford's Workshop manual

    upload_2021-7-29_13-28-23.png
     
  2. Rick Simons

    Rick Simons Member

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    My Dad always said "Check the grounding first".
     
  3. Where the bulbs leds? I tried using leds for the license plate lights, and the circuit decided it didn't like them (would blink twice when arming alarm just like the normal bulbs, but would not illuminate when running lights were on). I put standard bulbs back in and they work fine now.
     
  4. scramblr

    scramblr Senior Member S197 Team Member

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    Problem is tracing the wires back to the source through the multiple harnesses. Followed the above schematics as best as possible, but impossible to trace unless you take the wires out of the harness.

    I also think it may be the SJB since it's two different plugs. We'll see what the testing shows.

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  5. scramblr

    scramblr Senior Member S197 Team Member

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    Nah, regular bulbs and swapped out for brand new ones.

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  6. Juice

    Juice forum member

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    You dont have to pull wires apart. Just need to figure out which wires in what SJB connector go to the bulbs that do not work. Than with the sjb removed, continuity test the two wires going to the non-working bulbs. The hard part is figuring out which SJB connector!
     
  7. scramblr

    scramblr Senior Member S197 Team Member

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    I know, that's my point, short of pulling the wires apart, I don't know how to determine where they start and from which plug. Forscan tool comes in tomorrow so we'll see what that says.

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  8. scramblr

    scramblr Senior Member S197 Team Member

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    I decided to not kill brain cells on this for now, so I just spliced the two bulbs from the opposite sides of the car. Interestingly, I found the left side marker that isn't getting power (small plug), the ground wire is also not grounded. That gave me a headache for a few minutes trying to figure out why there was power (from the other side), but the bulb still would not turn on. So I had to ground the small plug and now everything works.

    It is possible, that I may have caused this messing with the BEC. I replaced the center tray (inside the BEC) due to it melting from the cooling fan, but I think the SJB fuses are in the first tray, so who knows. Something I'll trouble shoot when it's not 100* in the garage...or the SJB craps out all together.
     
    Last edited: Jul 31, 2021
  9. Pentalab

    Pentalab forum member

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    Why does water / moisture even getting into the SJB ?? Is there provisions for a drain ?
    Some silica gel / desiccant would / should solve solve moisture ingress problems.
     
  10. Joe combs

    Joe combs Member

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    The keys are not linked to the SJB... i have swapped several in my garage and never had to had to have 2 keys. Key data is not maintained within the SJB. Yes it needs to be configured for the car, but the keys have nothing to do with the SJB configuration.
     
  11. Juice

    Juice forum member

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    Keys/PATS are not affected by SJB swap.

    What needs to be programmed to/in SJB are vehicle specific options like:TPMS, keyfobs, fog lamps, rolling door locks, etc. None of that will keep the vehicle from being driven.
     
  12. scramblr

    scramblr Senior Member S197 Team Member

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    From what I have seen, it leaks to the top of the box and trickles down into where the harness' plug into the SJB. Then causes corrosion at the pins coming out of the SJB. Once that happens, the SJB loses it's mind. This guys has a decent video replacing it and at 7:20 shows the corrosion on the pins.

     
  13. 86GT351

    86GT351 forum member

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    OK. I guess the Work Shop Manual is wrong then?
     
  14. Juice

    Juice forum member

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    Wouldnt be the first time! I worked as a dealer tech for 15 years.
    I have become quite familiar with the SJB with this swap and wanting to add features I did not have (rolling door locks and oem fog lamps)

    1 Ford told me rolling door locks will not work on mine, they do.
    2 Ford told me they can enable fog lights, this was not correct. Even enabled, they still didnt work. I had to add jumper to bypass the SJB.

    So yea, I take info in shop manuals with a grain of salt. I lost track of how many times the diagnostic steps did not help me find an electrical issue.
     
    Last edited: Aug 2, 2021
  15. 86GT351

    86GT351 forum member

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    I get that. However basics like programming are not something they would be wrong about.
     
  16. Juice

    Juice forum member

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    My SJB was in "factory mode, configuration incomplete" when I first connected to mine. All factory options were working. To me that means at some point, something was done to mine and the programmimg was incomplete. Yet everything worked.
     
  17. Lime1Gt

    Lime1Gt Junior Member

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    According to my wiring diagram, if correct for your model year, Power to feed the problem lights comes from the SJB as you already know. If you were to remove connector C2280D from SJB and supply power to pin 16 Wht/Rd wire of the connector it should light the LS Marker. Supplying power to pin 31 Blk/Pnk of the same connector should light the Rt Park lamp. If they light the problem should be in the SJB. If they don't the circuits also run through the BEC on route to the lights. It's been awhile but I think the C2280D is the one closest to the floor on the back side of the SJB.

    Indecently, I had an issue when I had my 05 where I had added a brake/park sockets to the inner park rear lights so as to have all lights lit with brakes On. I just tied the brake wiring into the second bulb socket on each side. It lasted quite a while until one day I was in heavy stop and go traffic on a hot day. Those two brake lights went dead but bulbs were good. I ended up getting an electrician friend of mine to check the SJB board and he found a defective part that couldn't handle the load of the extra bulb on that circuit. He replaced the part, I think a transistor or i/c and I change the wiring back to factory.
     
  18. jewc75

    jewc75 S197 Junkie S197 Team Member

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    I was always under the impression the key data was stored in the gauge cluster.
     
  19. Jack F

    Jack F Junior Member

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    It is with the 10-14 cars. 05-09 is in the PCM.
     
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