I completed my sub install in my 2008 mini cooper hatchback. I used the integral audio harness and everything works good so far except I have a pop every time I turn on the car, it also hums with no audio and it randomly thumps (like when I unlock the car or something, but not every time). I actually followed the integral audio instructions when running the wires. I used the common ground they suggested on the passenger side. One small difference is that the cable I ran wasn't long enough by like 2 ft. I had no 8 gauge coupler at the time (getting one today), but in the meantime I put an electrical cap and sort of twisted it together and taped it together after capping it. My question is could the ground be messed up because of the cap and that's why I'm getting all these issues or could it be the Rca cables.

 

Sounds like a remote wire problem. Sounds like its turning the amp on when nothing is playing( the pop noise). And keeping it on when you turn the music off (the buzzing noise). Where did you tap for the remote signal?

 

From the pin 1 the solid black wire on the x15 connector. When the radio is turned off so is the amp though. I think it's a grounding issue though?

 

Maybe. I'd say call integral if you can't figure it out

 

A few quick tips, but I don't want folks to get the wrong idea here so before I start, just a reminder that those harness are an unsupported product. Support costs would be orders of magnitude higher than our complete products and we make almost nothing on them. They are provided only as a favor to the DIY community and sold only through a vendor on Amazon for just that reason. Ok, disclaimer over....

• The audio system should energize as soon as the car is unlocked, door opened, etc. This is required for door chimes, etc. It remains on as long as the vehicle is on, and then a bit after, regardless of whether or not you are playing music or even have the headunit turned on.
• If you are getting turn-on thump, then either the soft-mute turn-on on your amp is defective, or some other component is dumping a voltage pulse into the input signal chain after the RAD_ON signal is present.
• A poor splice (which it sounds like you've got) on your ground could create the resistance differential needed to create a ground-loop, BUT I doubt that is your issue here
• More likely you have the input sensitivity (sometimes incorrectly called gain) set too high on your amp. These OEM headunits can be noisy, and you have to keep the sensitivity down on the amp. The HU puts out significant voltage, you won't have any trouble getting your amp to full rated output, which you probably don't need anyway.
• Could be something else, but I'd bet on one or both of the above if I were you.

 

I'm fixing the ground cable later this week. In the meantime a ground loop isolator fixed all my issues. You think this points more to my ground not being good, or is it just one of those things because it's a factory Hu and stuff.