tail light & backup lights & brake lights on 1993 Mazda MX-6

when lights are off ,foot on brake ,right brake dim, right front turn light comes on dim.whith lights off, turn on right tun signal with foot on brake,flashes faster thin with foot off. & right turn signal indacater light on dash lights up with foot on brak & turn signal off, whith head lights on foot on brake,right brake light go"s out & back up lights come on. & with lights on right turn signal, foot on brake, the brake light flashes back and foth with turn signal. I have replaced flasher brake switch rear light checker. the problem stays the smame.I had alarm installed & stero, they havent worcked after that, the shop said thay are not responsabel.what could be wrong with my lights,?I checed continuity between ground & sockets is ok.the brake light warning light comes on the dash with foot on brake.

Asked by for the 1993 Mazda MX-6
Thanks for giving so much information. It all points to a defective ground circuit in the lighting systems, just for a starting point in diagnosis. Do you say that the problem started when you had the alarm and stereo work done? It's very common for a stereo/alarm shop to mess up the electricals, I've fixed many of their screwups in my day. Naturally they don't want to admit responsibility for the problem, they know that they can't fix it...
I'd say, go to an auto electrical shop or a Mazda specialist and keep away from stereo shops. Sorry, guys, I've seen some bad electrical work from those kind of shops. Just sayin'...
Find an electrical shop or Mazda guy and give the bill to the stereo shop. Won't help but they should know what they've done to your car. A good electrical guy can usually fix these kind of things pretty quick..
Here's a directory for you: