Please help. My car was sitting for a few months. When I press the signal light left, or right, BOTH signal lights blink inside on the dash and outside front and back FAST. Both sides. I replaced both headlamps, the whole unit. Still the same issue. My Hazard lights work PERFECT. My fog lights are both blown out, but they have been for years. I ordered new fog lights so I will see what happens with that tomorrow. I also replaced the "Turn Signal" 15 amp fuse on the inside dash

 

I think the first step is to stop randomly replacing stuff and spend the time and effort instead on diagnosis. Break out the multimeter and wiring diagram and start checking the circuits involved.

Id suspect turn signal switch first, so personally Id probably start at its harness checking outputs as you work the switch.

 

Re-establish your ground connections too.

 

New to this forum and am currently having similar issues.

Got my son a 2002 MCSS and this community has been a great help getting it up to spec.

First issue with the lights was the turn signals flashing a couple o times then quitting. I replaced the hazard switch and now the signal lights stay on, but flash rapidly. I resurfaced the front grounds above the headlight and when I was still having issues, I spliced the wires and tied them directly to the ground screw. Still same issue.

Questions is, fog lamps light ground and easiest way to access it. Also, any other input would be greatly appreciated. Thanks in advance.

Spliced top ground above driver headlight