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I'm fairly new to the group and haven't posted much before. If this topic has been covered, I apologize. I searched high and low and could find much on this topic so I'll share my experience and ask my questions.

So, 2 weeks ago my wife had a new cat-back custom exhaust fabricated and installed for me for my birthday. I spec'd it out with a local (Houston) shop and all was great. Very happy with the sound, quality of work, etc...

Friday night, I am driving home from the Street car night at the Drag Racing track about 45 minutes away from my home (I got there fine) and the car starts throwing a bunch of codes. All systems seem to be failing, one after the other. I pull over, shut it down then attempt to restart the car and it just flashes the lights on the display/gauges but the car won't start. I turn on the flashers on the side of the toll road get out, check the battery connections, nothing odd.

A few minutes later I try again to start the car, it's completely dead. Battery is drained. I can't even get it to go into neutral. I have to have the car towed home.

I put a charger on the battery after I got home. Saturday morning, I inspected the car and found something odd.

There appears to be a ground wire/strap that was connected to the stock exhaust on one end and one of the rubber exhaust mounts at the other end. When my new exhaust was installed, this was left disconnected and the new custom exhaust doesn't have a place to connect this.

I started the car right up (had to reset the clock) and drove it to my local dealership. About a half mile from the dealership, same thing as Friday night. All systems started to shut down, tons of error codes and the car limped into the service department. They are going to get to it in the next couple days.

I can't find anything other than a little bit of information that says this is NOT a ground wire for the electrical system but a Static electricity discharge ground.

Everything I have found seems to point to my problem being the alternator going out BUT, anyone have any ideas here? Is it just a coincidence or does anyone else know anything about this ground connected to the stock exhaust.

It seems like a really strange place and configuration for a critical ground wire for the electrical system.

Any help/Input would be greatly appreciated.
 

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I'm fairly new to the group and haven't posted much before. If this topic has been covered, I apologize. I searched high and low and could find much on this topic so I'll share my experience and ask my questions.

So, 2 weeks ago my wife had a new cat-back custom exhaust fabricated and installed for me for my birthday. I spec'd it out with a local (Houston) shop and all was great. Very happy with the sound, quality of work, etc...

Friday night, I am driving home from the Street car night at the Drag Racing track about 45 minutes away from my home (I got there fine) and the car starts throwing a bunch of codes. All systems seem to be failing, one after the other. I pull over, shut it down then attempt to restart the car and it just flashes the lights on the display/gauges but the car won't start. I turn on the flashers on the side of the toll road get out, check the battery connections, nothing odd.

A few minutes later I try again to start the car, it's completely dead. Battery is drained. I can't even get it to go into neutral. I have to have the car towed home.

I put a charger on the battery after I got home. Saturday morning, I inspected the car and found something odd.

There appears to be a ground wire/strap that was connected to the stock exhaust on one end and one of the rubber exhaust mounts at the other end. When my new exhaust was installed, this was left disconnected and the new custom exhaust doesn't have a place to connect this.

I started the car right up (had to reset the clock) and drove it to my local dealership. About a half mile from the dealership, same thing as Friday night. All systems started to shut down, tons of error codes and the car limped into the service department. They are going to get to it in the next couple days.

I can't find anything other than a little bit of information that says this is NOT a ground wire for the electrical system but a Static electricity discharge ground.

Everything I have found seems to point to my problem being the alternator going out BUT, anyone have any ideas here? Is it just a coincidence or does anyone else know anything about this ground connected to the stock exhaust.

It seems like a really strange place and configuration for a critical ground wire for the electrical system.

Any help/Input would be greatly appreciated.
I would start by telling us what codes it exactly is throwing. A loose GND wire is an unlikely cause as exhaust is not a ground return for e-power. Typically, they just want to ensure it does not build any static when it corrodes. So, I would reconnect, but it is not urgent. When they installed the exhaust, did the replace all the heat shields properly. If not, you may have toasted some wire harnesses maybe?
 

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Discussion Starter #3
Thanks for the response.

The heat shields were not removed during the exhaust install.

The system messages were significant. Braking system failure, SMG Failure, Stability control failure, Orange Cog. It was like all systems were shutting down one after the other with no pause in between until the entire System shut off and no iDrive display at all.
 

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Sounds like you lost the alt, or regulator on your car. Once the system voltage drops below the 13 volts, the car will start throwing codes as its systems can no longer function at the lower voltage. And, based on your battery being totally dead, I would start there. These cars like their voltage stable, and when its not, it becomes very unhappy.
You can search the site for other that have had the same experience as you.
 

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Discussion Starter #6
I think the answers so far confirm my concerns.

1. The ground strap connected to the exhaust is not critical to the electrical system and is not the culprit and is unrelated. I'll chalk this up to coincidence.

2. It appears that the alternator went out (maybe the regulator)

Now that I am armed with some information, I can be prepared to intelligently discuss this with the dealership when they call and tell me it needs $5k or more worth of work and that it won't be covered by my warranty (because this is always what the dealership does)

To answer the question about the battery being disconnected. No, they did not do this. I did watch the work being done to make sure the exhaust guys treated my toy with great care and didn't see any time that they were welding where something might be damaged. So, unless there was some sort of wiring running under the heat shield in the exhaust cutout area under the car, I think I am fine here. It would be a really poor design to run any wiring in the exhaust cutout between the heat shield and frame. That would surprise me.
 

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The string of error codes were similar to mine when my voltage regulator/alternator went out. The repair cost at dealer labor rates will be about 1 - 1.5K including the replacement parts for the voltage regulator/alternator.
 

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Discussion Starter #8
Just got off the phone with the dealership. It was the alternator. $1650 to replace, Aftermarket warranty will cover it, $50 out of pocket for me.

Thank you everyone for the input.

This worked out as well as could be expected.
 
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