My truck is running pretty okay now, but I noticed that the lights, along with pretty much all electrical stuff, except brake light and heater are not working. Well that leaves me just the lighting and dash wiring on these old trucks. Also noticed is the old wiring insulation made of cotton gauge type insulation is literally disintegrating as I try to trace the wire. So the truck gurus... I have 2 questions.

1. Does any one have a wiring diagram with wire sizes noted?
2. Do you know where I can get wires with different color insulation and tracers?

I know, there are ready made wiring harnesses, but what is the point in buying one of those when you can build one for three times the cost and takes 12 months to complete? Knowing that you built it, and barely works... priceless.

 

Look in my #4 gallery for the diagrams.

The top drawing below indicates what AWG to use on which item for a 12 volt system - 6 volt is 1 to 2 AWG bigger if you are staying with the stock 6 volt system. It is not the correct wire flow for the 51/52 use the lower drawing for where the wires run, the upper for sizes only.

Napa has wire in all the colors and sizes you need.

Here is a link to an electrical supply place that is well thought of:

https://www.ford-trucks.com/forums/8...-supplies.html

And a wiring diagram with wire sizes on the 56 (this is for 12 volt applications - 6 volt requires larger wires)

The second drawing is the signal flow for a 51/52

 

Exactly what I was looking for. Thanks Julie.

 

One more thing... Are you sure the diagram is for a 12V? The battery shows 3 cells. Maybe it is mistake in the diagram. Anyways, thanks for the information once again.

 

Well, it's kind of iffy! It's kind of a mix mash. You are talking about the top one right?

The reason I say it's 12 volt is because the wiring configuration - specifically the headlight switch/power distribution - is unique to the 1956 F-100, which was 12 volt. The earlier trucks used a twin pack of circuit breakers to distribute power off of.

However on closer look, there is a temperature sender and a temperature switch for the V8 engine. That was only done on the Flatheads and by 1956 when the change was made to 12 volt, there were no flatheads installed in Ford Trucks.

In looking at the wire sizes, they will be ok for 6 volt if you stay with a 35 amp (stock standard duty) generator. If you are converting to 12 volts, the wire sizes are more than ample even with a 75 amp alternator.