Having searched the forums extensively I have been unable to find the correct color and gauge wires I should use for running from the front firewall to the rear taill ights. My aftermarket turn signals have blue and red. The taillights black and white. Also note I have an aftermarket trailer light set up and have converted to 12 volt with Alternator. I was thinking of adding a terminal block near the rear tailights under the bed to clean up this mess (pictured). I realize I may get advice to install a brand new wiring harness complete but want to hold off on that project when I tear the bed and cab apart.Thanks for any help.
16ga or 14ga works. Any color works. Colors don't matter on simple old truck wiring. Especially since you will be doing a new harness at some point. Colors are to be able to follow and trace (and to some, to be purely correct). Tracing is easy to do with our vintage trucks most of the time. Since you are adding the wires, you know where they will go. Don't sweat the small stuff. Adding a terminal block is a bad idea. It introduces a place for corrosion, can come loose, adds resistance and is unnecessary. Splice with crimp or solder and cover with shrink sleeve............best to run a whole new wire from switch to light if you can. That way at least you are using a continuous color. Colors used on aftermarket turn signal switches don't always match colors used on wiring harness kits...but that's OK also.
Watch out for careful drivers!!! I'm away on an ego trip. Will be back on Feb 30. I'm not an Auto Mechanic, but I play one on TV. I charge $0.02 for every opinion and I take Paypal. Plan B is always better than plan A, by definition.
I’m using a 4 wire boat trailer harness. I terminated the chassis wiring in a typical 4flat car side. The. The bed uses the trailer side wiring and color scheme. I went with the boat trailer harness because it splits the tail into 2 separate browns at the connector. To add trailer lights ypu can get a 12” 4flat extension and T off of that to a second trailer connector at the hitch.