So after my friend helped me install my audio system (removed all original speakers and head unit, wired 2 mids, 2 tweeters, and 2 small subs to 900 watt 5 channel amp) my car has been having odd electrical problems.

When my speeds are low, turning the wheel all the way, or pulling into/out of the driveway, and randomly when at stop signs or slowing down will cause all electrical systems to turn off and then back on again (audio, power steering, etc.). The car doesn't die, but the electrical just goes out for a second or two before coming back on. My mechanic couldn't replicate the issue and of course it happens all the time when I'm driving the car. The voltage at the battery is good (12.4v) and goes to a bit over 14v when the car is running so it doesn't seem like a battery or alternator issue, but rather the way my audio is wired.

I tried labeling as much as I could in this pic of the amp and wiring in the back, but I'm not super familiar with how everything was wired here. If anyone could provide some insight to this problem that would be great, thanks.



UPDATE:
After driving around for a bit with the system off, the check engine light turned off and in each situation where it would have lost power/turned back on, it didn't occur, attributing the problem (most likely) to the audio system.

After this I pulled the head unit out to take a look at the wiring up front, and it appeared to be pulling power from the stock harness' 12v constant, rather than the 12v power that was ran from the AMP to the front, as seen in the pic posted. I plugged the head unit into the 12v running from the amp and drove around for a bit without issue. Granted it was a pretty short run, we'll see if this swap in where it's pulling power from has changed anything.

UPDATE 2:
So it's still happening, but I did get the CEL code, it's P0500 Vehicle Speed Sensor "A". No other codes were found. After searching around a bit, it seems pretty odd that this is the error code given I haven't touched the ABS or any other speed sensors. Was hoping I could resolve this myself but may have to go in for this one.

 

Did you install a capacitor?

 

We did not, I've never seen a capacitor installed in car audio, but after taking a look it seems more useful for higher power systems? May be wrong here since I'm not familiar.

 

in your application I wouldn't think it would be necessary but it's something to think about. Do you have any issues without the stereo on?

 

Your MINI has electric power steering which is under the most load in all the situations you're having issues in. Are you only having issues with the stereo cranked, or anytime? Does it happen with the stereo off?

 

I started testing today with the system off, so we'll see if it happens at all while it's off. Another thing is the check engine light came on as well.

 

I'm doing some driving today with the system off, but it doesn't matter if anything is playing through the system or if it's at 0 volume, just while it's turned on these problems occur. I'll update after driving around for a bit with the audio system off.

 

After driving around for a bit with the system off, the check engine light turned off and in each situation where it would have lost power/turned back on, it didn't occur, attributing the problem (most likely) to the audio system.

After this I pulled the head unit out to take a look at the wiring up front, and it appeared to be pulling power from the stock harness' 12v constant, rather than the 12v power that was ran from the AMP to the front, as seen in the pic posted. I plugged the head unit into the 12v running from the amp and drove around for a bit without issue. Granted it was a pretty short run, we'll see if this swap in where it's pulling power from has changed anything.

 

Get the error code. If you don't have an OBD reader, go to a parts supply store such as AutoZone, O'Reilly, etc and they can do it for you.

 

The check engine light turned off, and until today I thought the issue was solved with the head unit power source swap, but it happened again today when pulling out of a driveway slowly (the check engine light did not come back on) so back to the drawing board.

If it does come back on though I'll try to get the error code.

 

Update! So it's still happening, but I did get the CEL code, it's P0500 Vehicle Speed Sensor "A". No other codes were found. After searching around a bit, it seems pretty odd that this is the error code given I haven't touched the ABS or any other speed sensors. Was hoping I could resolve this myself but may have to go in for this one.

 

After driving around for a few days with the audio system off (out of frustration sorta), the same issue came up. So more than likely not related to my audio system as I originally thought, could a mod possibly move this to a more related section?