I just bought this car 1989 RS V-8 5-SPEED All power car.When I push the brake pedal all the running light's..(not head light's)..and cluster light's come on and the buzzer for when light's are left on come's on.Let the brake off and all of it goe's back off.When I turn the light's on the brake light's come on with the other light's.There was an alarm in the car with a after market stereo that was removed but don't think that would be it because all the wire's were left there.Everything was just unpluged and it was a nice clean installation.Someone told me to replace all the bulb's and that might fix it?????THAT'S ALOT OF BULB'S.....Thanks for any help with this problem......Tim.

 

that is correct that a faulty bulb could be the cause-
you only have to check the bulbs for the brake lights,
the bright filament in one of them might be broken or
distorted out of shape and making contact with the
low wattage running light filament in the bulb-appling
power to the running light circuit when the brake lights
are activated.Could be short between the two circuits
too, but a faulty bulb is more likely

 

Found it.The problem was one bad buld on the left rear tail light and the wrong in the right....Thanks for the help on it...........Tim