Correct Wire Gauge Selection

[kajf9491]

I'm hoping some of you much more knowledgeable and experience members may be able to easily answer this for me. I've been slowly working through different electrical issues with my 72' longbed but I haven't been able to find anywhere that recommends what gauge wire should be used. I think I bought a few spools of 16ga and that's what I've been using but I'd feel much more comfortable if I knew this was correct. Any Recommendations?

[SS Tim]

The factory service manual has the wiring diagrams indicating color and wire gauge for most of the circuits. They can be found in section 12. Most of The generic charts do the same but often come up short on option wiring.

RTFM ... Read The Factory Manuals... download 'em here

[kajf9491]

Thanks TIM! That link to the manuals is like gold! You probably just gave me access to the answers for hundreds of questions I would have had.

[87Skier]

Some general rules:

Low current stuff (less than 5 amps) - 18 awg (Side marker lights, relay control wires, instrument lights)
Med current (5-10 amps) - 16 awg (Tail lights)
Med-high current (around 10-15 amps) - 14 awg (Headlights)
High current (20+ amps) - 12 awg (Coil wire, heater fan)

Over 30 amps you will have to size to what you are doing.

Size a little bigger than you need. If you are doing a long wire run, you may need to upsize your wire. Don't be tempted to use 20 awg and higher number wire for automotive stuff.

[FirstOwner69]

Gauges and colors shown here:
http://67-72chevytrucks.com/vboard/s...d.php?t=185665

[jabborabbo]

I would add to make sure EVERYTHING is appropriately fused...for instance, in my '67 the cigarette lighter originally had a 12 gauge wire running to a hot terminal in the fuse box...no fuse...I connected a fused jumper between that wire and the fuse box. Better to blow a fuse rather than melt a lighter or a wire....

[magwakeenercew2jh]

Originally Posted by jabborabbo

I would add to make sure EVERYTHING is appropriately fused...for instance, in my '67 the cigarette lighter originally had a 12 gauge wire running to a hot terminal in the fuse box...no fuse...I connected a fused jumper between that wire and the fuse box. Better to blow a fuse rather than melt a lighter or a wire....

Funny, but to me that's the most dangerous circuit in the truck.

Fuse. Fuse all the way.

[centuryhouse]

Because it is NEVER fun to be driving down the highway one night and have smoke come pouring out from under your dash. Ask me how I know

Oh that 67 Mustang was a fun car....but I knew nothing about wire gauge requirements when I rewired some of it.

[dirtyjim]

here is a handy dandy wire chart