2004 Peterbilt 379 braking/turn signal issue

regardless. that junction box at rear of truck is nasty and corroded. grounds are all f'.ed up.
https://www.amazon.com/MICTUNING-Wa...t=&hvlocphy=9007357&hvtargid=pla-759801914040

 

That's a good idea and I'm kinda mad I didn't think of it. Every year my rear S/T/T harness gets shorter and shorter.

 

If your going to make the day out of it, get rid of all the old wires as well and run this duplex wire or triplex if you need 3 wire.
https://www.amazon.com/Duplex-Tinned-Marine-Wire-Black/dp/B00MI52TA4

To add new pigtails to lights, don’t bother using junk connectors ore solder iron. Watch a YouTube video on how to use these and then for added protection slide a shrink tube over them. You will have made yourself years of trouble free service.

https://www.amazon.com/dp/B089D5GD4...=8g63u&ref_=sbx_be_s_sparkle_mcd_asin_1_title