Toyvo,
The aftermarket turn signal kit that JC's and others sell has a little metal bracket for adding a second bulb to the inside of the turn signal assembly. I bought and installed that kit. There are now three filaments in each tail light.
It does not work too bad. I have since upgraded to an aftermarket turn signal switch..the one with 8 or 10 wires that runs the brake light power through the signal switch. I am in the process of finishing the wiring so I am not sure how old system VS new will work...
I also added a right side light when I did the upgrade and added turn signals two years ago. The new wiring harness only has a brake and running light wire to the rear of the truck. That is the part I am not sure how to wire up...
Maybe someone will chime in and tell me how it all will go together in the end, but for now, I am leaving the two bulb system in place as a Just in Case...
