possible short?

I have an 03 GTI vr6. It is turbo'd and i have a lot of aftermarket gauges installed. sometimes when i press the brake pedal, all of the dash lights come on, and the directional arrows on the dash light up ( although dimmer than usual) . Also, sometimes while this happens, the rear wiper arm will go halfway up and stop. When i try to use a directional, it works normally,until i step on the brake pedal, then they just both flash in rapid succesion ( the interior directionals i mean) and they dont light up on the outside. This only happens sometimes, otherwise it works fine. Also, sometimes when the car is off, and i press the lock button on the key fob to arm the alarm, the rear wiper arm will move a little bit. I can actually make it keep moving by continuously pressing the lock and unlock buttons on the key fob. So those are the symptoms, here are the steps i have taken so far to try and correct this.
1 changed all rear bulbs.
2 checked for loose and bare wires in gauge connections
I also have a QTP exhaust cutout installed. I kind of want to say that i think this problem began shortly after this was installed, but i cant really be sure.
Please help