Please help. I purchased a LED third brake light for my 95 jdm mini and installed on the rear parcel shelf. I connected it to the right rear tail light circuit. Works great when no headlights/taillights are illuminated but once the main headlights are on it flickers continuously. Pressing the brake pedal illuminates the new light but after a few seconds of releasing the brake it starts to flicker again. I tried changing the ground to the negative battery terminal without success.
My search on the forum did not turn up a permanent solution to this issue. Would appreciate any input.