Cadillac Repair: 1988 Coupe DeVille, turn signal switch, side marker

Question
I'm trying to figure out how to repair the front side marker lights.  The left front lights up fine when turning on the turn signal switch, but when I turn the right side on, the turn signals work fine, but the side marker dosen't light up.  I've changed the bulb, but have found that there is no power to the socket and the wiring looks fine tracing back as far as I can go.
You assistance would be greatly appreciated.

Answer
In the socket that the bulb fits into does the other contact test out to be a GROUND ?. Check the ground wire located  on the right hand side of the engine compartment just ahead of the left hand wheelhouse.

Locate the 3 or 4 wire electrical connector  behind the head lights on the drivers side to see if you have battery voltage on the DARK BLUE wire.

Are you POSITIVE that you are using the CORRECT SPECIAL bulb ?.