Instrument panel lights come on when brake pedal is pressed down

[Bortoray]

Thanks for reading my thread you guys.
Ok here is my problem. I have a 1997 318is. I recently had a upgrade to my stereo. I had 2 speakers installed up front and a amp and a sub.
Every since then I have had an issiue with my instrument cluster.
First when I turn on my lights the rpm gauge will drop to 0 rpm and then go back to normal idle. Now after the car stereo install place checked on my stereo because the deck was not getting any raido reception. When I press the brake pedal the dashboard warning lights come on and so does the warrning bell. It does not happen all the time but it happens alot.
What do you guys think is the problem.
Thanks for you help.
ps I have checked the battery connections and the wires going into the deck.

[fun2drive]

I think you have an issue with a ground or they spliced into part of the instrument harness.
I would ask them to try another ground location.
If that is not the deal than something is feeding back to the instrument panel to cause this. They could put a blocking diode in place so that no power can flow back to where ever they pulled power from.
BMWs are the most picky car I ever worked on in this regard. I had my panel out once and had to disconnect the intensity switch for the panel and my panel malfunctioned. Plugging it back in allowed it to work fine.
Really picky like I said...

[LockDots]

Did you install the radio or did somewhere install it for you? I had a very similar issue with mine where when I turned off the car the radio and instrument lights would stay on until I hit the brake. Turned out that when my stereo was installed the Amp Turn-On wire was spliced in along with the Power Antenna Turn-On wire. Pull the radio and make sure you only have the amp turn-on wire connected (usually blue) and nothing else along with it. While you're at it also check to make sure that the dimmer/illumination wire are not hooked up. Unless you're very install-savy i'd stay away from this wire as it could cause even more problems.

Here's a before and after video of my symptoms and fix.

http://www.youtube.com/watch?v=Kq2NePws-OI

http://www.youtube.com/watch?v=oZjh4GQvzp0

[Vividkid82]

Spagetti!!!!

[Bortoray]

Thanks for the replies. I pulled the deck last night and the instrument cluster did the same thing once or twice even when the deck was not hooked up. When the deck is hooked up it does it alot more. The wire harness was a mess so I cleaned it up as best I could.
The wire going to the amp from the wiring harness that plugs into the back of the deck is running straight to the amp. They have it running through the instrument cluster bay and under the lower dash panel and then along the running boards to the back of the car leading to the amp. The yellow wire that is power for the amp is hooked up to a blue wire on the harness that plugs into the deck. The amp is hooked up directly to the battery with a fuse in between the + battery terminal, and the ground for the amp is hooked up to the - terminal on the battery.
One thing I noticed that concerns me is that there is a cord that is taped up with the antena cable and it is not hooked up to anything. It has a metal connector that looks like it is supposed to be plugged into something but I cant find what it is.

I did recall that the dimer/illumination wire was hooked up. It is orange on the harness that plugs into the back of the deck. I am going to pull it ASAP and let you know. Thank you sir!!!! :buttrock