08 bullitt electrical problems

[nieo]

Hi, I have a 08 mustang Bullitt that got shifted from 4th to 2nd (wasn't me) that will probably need a clutch, but I haven't even been able to get it started to see. The gauge cluster doesn't come on, windows don't work, no interior lighting or headlights (basically nothing works), but the tail lights won't turn off unless I pull the battery. Fuses 47 and 42 in the engine bay fuse box, and 17 in the smart junction blow when I turn the key to accessory. Fuse 8 in the smart junction box blows as soon as the battery is connected. Thankful for any help I can get I feel like im tearing the car apart trying to find the problem.

 

[Dino Dino Bambino]

It sounds like you have a wiring harness shorting out somewhere. You might want to check if any rodents have been feasting in it for breakfast.

 

[asdrew]

My first step would be pulling the SJB, opening it up, and cleaning all the connector pins and wiring plugs.
When they get corrosion and have intermittent/arcing connections, many electrical gremlins invade your car.
Eliminate those and the rest of the troubleshooting should be less complicated.

 

[nieo]

All of it happened right when it got shifted from 4th to 2nd, is there anywhere in the wiring harness that’s next to the transmission it could have damaged?

 

[Forty61]

So I have a few questions that may help diagnose it..

1) All these electrical issues started immediately after the bad shift?

2) Were there any existing issues/gremlins BEFORE the shift issue?

3) The car has not sat for any time? Signs of water intrusion/rodents?

To properly diagnose you need to isolate the problem. If this all started right after a missed shift I struggle to see any correlation to a mechanical mistake.

I would find a shop manual or wiring diagram and see what all those fuses tie to, that should point you towards what system has issues. I would then unplug whatever those fuses go to and throw power back to it, if they blow again it's an issue in the harness, if they don't blow then it's a component downstream. I would also lay eyes on the SJB and fuse box as others mentioned just to rule out any weird issues there.

 

[asdrew]

It's possible that the abrupt shift jarred a poor electrical connection looser somewhere. That happened years ago on Wifey's Suburban when she jumped a curb and blew out a tire. The dealer wanted $$$$ to replace the ABS system and I fixed it for free by redoing some connections.

 

[JC SSP]

I was thinking of the exact same thing… violent shock to the drivetrain shook something loose…

Post some pics of the Bullitt.

 

[nieo]

update, after a lot of troubleshooting my running theory is that the alternator / voltage regulator is bad and it caused a voltage surge that took out most of the major modules on the car (cluster, PCM, radio, SJB etc...) working on replacing all of that now

 

[Juice]

update, after a lot of troubleshooting my running theory is that the alternator / voltage regulator is bad and it caused a voltage surge that took out most of the major modules on the car (cluster, PCM, radio, SJB etc...) working on replacing all of that now

I find that theory highly unlikely. The battery should have absorbed any damaging surges.
Ive only seen lightning strike "fry all modules" at the same time.

 

[nieo]

I can't think of any other reasons, it happened while it was running. I also found out the battery was bad (like .1v bad) and it had to be jumped to get it started.

 

[Juice]

I can't think of any other reasons, it happened while it was running. I also found out the battery was bad (like .1v bad) and it had to be jumped to get it started.

That makes more sense, the shock killed the battery. That can fry electronics.