I have a newly bought truck with a left hyper flash turn signal. What it does is three normal flashes then starts flashing very fast., Spent $500 at chevy dealer with no luck only to find out the harness was cut into and spliced. Dealer recommends new main harness. So I`m trying what I can before that expensive option.
Can anyone tell me the color of the left turn signal wire coming from the front of the truck in the main wiring harness running under drivers side to the back of the truck? As it goes into the left rear turn signal it is a yellow wire for turn signal bulb thats all I can see. What happened is the main harness was cut and had about a foot of it removed around where the bed and cab meet then spliced all back together with butt connectors using wire all the same color. As I said everything works fine just the left turn signal flashes super fast after three normal flashes?
Dealer checked:
All left side Bulbs
Grounds
Installed new BCM control module
Found section of harness cut out then resplice together ( dealer thinks that's the problem area but not sure) had them stop there because of continuing cost.

Thanks for any advise!

 

Left turn is yellow, Right turn is green and Brown is marker lights