Anyone know of an electrical expert who may be able to help diagnose recurring electrical issues with a 2012 Mustang, V6 automatic? The car has sentimental value as my wife's first major purchase in college, and we've been beating our heads against a wall off and on for years trying to get it running. We've replaced battery, alternator, PCM, instrument cluster, ignition switch, cleaned the ground connections, bypassed the anti-theft system, and probably another handful of things, some at home, some at the dealer, some at a shop. Sometimes it starts, others not, but even when it's running the dash will intermittently go dark, gauges to zero, lose power steering, and then suddenly turn back on.

Any help or leads (preferably in the Houston area) would be much appreciated!

agcoop10 said:

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Anyone know of an electrical expert who may be able to help diagnose recurring electrical issues with a 2012 Mustang, V6 automatic? The car has sentimental value as my wife's first major purchase in college, and we've been beating our heads against a wall off and on for years trying to get it running. We've replaced battery, alternator, PCM, instrument cluster, ignition switch, cleaned the ground connections, bypassed the anti-theft system, and probably another handful of things, some at home, some at the dealer, some at a shop. Sometimes it starts, others not, but even when it's running the dash will intermittently go dark, gauges to zero, lose power steering, and then suddenly turn back on.

Any help or leads (preferably in the Houston area) would be much appreciated!

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It's trying to tell you it's time for a Coyote and TR-6060 swap.

Seriously though, it could be the fuse box, especially if it ever got any water in it. That can also fry the wiring harness.

What are the off and on voltages? I had a replacement alternator in my 2007 GT that was spitting out 17 -18 volts and caused a lot of weird behavior. Fried my heated seats for good.

Turn key to on and start wiggling stuff under dash and under hood and see if you can make the cluster spaz. Either you have a short or a bad ground somewhere. Either way the first step is figuring out how to reproduce the issue
Edit: is it a side post battery? I had similar happen on a vehicle a looong time ago and it ended up being a loose side post connection
Edit2: i assume you've googled up issues with the transmission lead frame in that vehicle? No codes? No other driveability issues/weird shifting?

Clean all positive connections as well

Robert at Auto Techtronics in Katy is great with electrical issues.

aggieforester05 said:

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agcoop10 said:

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Anyone know of an electrical expert who may be able to help diagnose recurring electrical issues with a 2012 Mustang, V6 automatic? The car has sentimental value as my wife's first major purchase in college, and we've been beating our heads against a wall off and on for years trying to get it running. We've replaced battery, alternator, PCM, instrument cluster, ignition switch, cleaned the ground connections, bypassed the anti-theft system, and probably another handful of things, some at home, some at the dealer, some at a shop. Sometimes it starts, others not, but even when it's running the dash will intermittently go dark, gauges to zero, lose power steering, and then suddenly turn back on.

Any help or leads (preferably in the Houston area) would be much appreciated!

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It's trying to tell you it's time for a Coyote and TR-6060 swap.

Seriously though, it could be the fuse box, especially if it ever got any water in it. That can also fry the wiring harness.

What are the off and on voltages? I had a replacement alternator in my 2007 GT that was spitting out 17 -18 volts and caused a lot of weird behavior. Fried my heated seats for good.

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This. Very good suggestion.

Think outside the box on this.

I'll add to this that a detailed inspection of wiring for rodent damage would worth your time as well.

I'm guessing it has the same overly complicated and fragile positive terminal contraption that connects to the battery post that my 2013 Shelby has. I would check that very carefully and possibly replace it. I have not had problems with the Shelby yet but had a similar setup on a 2013 Explorer that caused problems and eventually had to be replaced. Check it real good for corrosion.