I am at my whits end. I have a 1999 Ram 2500 Diesel. Here is what the problem:
Left Turn Signal Hyper flashes. The front Left bulb flashes but it is the parking light element that flashes
Right turn signal no issues, works perfect.
Left Parking light does not come on when lights are turned on but the left turn signal will glow steady if the left turn signal or hazards are not on.
Right parking lights are good
The speed (cruise) control servo will click on and off and so will the hood work light. when the left turn signal is turned on.
If I remove the Left front Parking/Turn bulb the issue with the indicator coming on steady with the parking and or head lights is gone. Of course it still hyper flashes since there is no bulb
I have replaced all the bulbs and I have swapped bulbs around with no change in symptoms

There is no visible damage tot he wires. I have pulled the driver's side battery and tray and looked all over. Nothing stands out.

Please help, I have a trip coming up in a few weeks and need my truck.

 

Got a short, or a bad ground somewhere. Start by looking at the back of the headlight switch, they are notorious for causing some issues. You can download the factory service manual from here, wiring diagrams are in section 8w. Have a look, and the problem may become apparent.

 

I found the problem. The ground wire from the socket to the ground junction C123 had 1K Ohms of resistance. I installed a jumper from the socket directly to battery ground. The problem went a way. Instead of trying to pull the old wire out and replace it I will just leave the jumper in.