For the sake of not making this long I have a 2001 Ram 2500 5.9L Gas but it has 96 wiring do we'll say it's a 96 Ram.
Problem: When I engage the left turn signal it causes my park lights to flash (passenger side lights up real dim but my clearance lights flash and my overhead console dims). Now when I turn in the headlights it doesn't turn on the park lights but it signals real slow, and from what I can see it doesn't affect the rear park lights with headlights on.
What I have tried:
Changing both turn signal bulbs
Checking for bad grounds
Checking for an open circuit
Literally checking all the wiring in the cab and under the hood for breaks

The only thing I found was at Joint connector A behind the gauge cluster is if you eliminate Pin #10 it doesn't do it. (I put a jumper wow to pin # 4&5) but as soon as you connect #10 to the circuit it does it. I'm at a loss here. Please help lol

 

What does pin 10 do?

 

I confused the pins up but basically you have 4 park lamp switch sense wires that come to a connector, and they use a copper plug to connect then together. I'm missing pin #9 but all that does is Don the factory radio (I have an aftermarket radio). #10 comes from the headlight to know when park lights come on. #4 is park lamps for license plate lights (don't have any connector to plug then into is gone) and #5 is park lamp switch sense for overhead console dimming and clearance lights

 

Got a bad bulb socket??

 

See I thought about eliminating the left one to see if it still does it. But I'm not at my house and have a Phillips screwdriver. I'm not McGiver and I can't wire with a screwdriver

 

Slacker. I thought marines could do better than that.

Are you still on the left coast?

 

I had similar problems... turned out to be a grounding issues. I just grounded out the pigtail off the turn signals up front on both sides - problem when away. The real issue is the monster mass ground point under the battery... there must be 20+ wires coming together there, and it seems to be a common fail point. As some point I'll address mine, but I pulled another harness so I could experiment with fixes before I modify mine.

 

Do you have a picture of what you are talking about?

 

I'll get a pic in the morning... which do you want, the hack or the mass ground?

 

Both please