May sound like a stupid question: I want to rewire all the visible wiring on my roadster (to the fan, the coil and so on...). What qauge do I need? 12, 14, or 16? If possible I want to buy just one or two diameters... thanks for your advices!
Wire gauge will depend on the load it carries. I would think you would like to run different color wires to identify the circuit. Check out Brillman @ the link below, they sell buy the foot, have lots of colors and tracer colors, and have excellent customer service. http://brillman.com/store/
Does not sound like a stupid question at all. The size of the wire varies according to the load. Easiest way to figure this out is to get a wiring diagram, wire sizes are marked on it. You can buy a wiring harness for hot rods but I don't know if anyone makes one out of cloth covered wire. Most common wire sizes for 12 volt would be 18, 16, 14,12,10 but could be as big as 1 (6 volt battery cable) or 2 (12 volt battery cable). 10 or 12 to main feed for fuse panel, headlight relay or engine cooling fan.
The same ga as the wire it is replacing. If it has 16 ga on one circuit then you will need 16 ga to replace it. Same with the other wires. Yes you can buy cloth covered wire by the foot. You will find out that in most cases the cloth covered wire is actually regular automotive wire with a fancy covering over it just for looks. The nice thing about your undertaking is that you can measure exactly what you need and only buy a foot or so longer and replace only what you need. My truck was done this way. The harness in the engine compartment is also covered in a woven typical 40s style harness. Only the wire that is out in the open has the fancy covering. I'm guessing that it was a cost thing.
"You will find out that in most cases the cloth covered wire is actually regular automotive wire with a fancy covering over it just for looks." This is correct. The old type wire was insulated with a rubber compound. The rubber was prone to deteriorating from exposure to sunlight, oil, gas, and to drying out and cracking with age, and even crumbling to bits. So they protected it with a woven cotton cover. When vinyl insulation became available in the early 50s it made the woven cover superfluous. Some of the old weaving machines from the 30s and earlier survive. Makers of woven covered wire buy vinyl covered wire and add the covering. These days it is purely for looks.
the hot rod company also sells cloth wires. The link is below http://www.thehotrodcompany.com/shopnow/show_dept.asp?dept_id=66&filterkey=prc
Your car originally ran 6 volts which requires a heavier gauge wire. If you are now 12 volts, theoretically you can place wires of half the size to accomplish the same tasks. Most 6 volts systems mainly use 12 and 14 gauge wire for lighting and accessories. Heavier gauge for the main lines from generator and to fuse block, and obviously battery cables.
One good thing to remember is that using wires that are too big (lower gauge number) does not cause a problem. Ask the supplier of the wire how many amps they can carry and work from there. Charlie Stephens
I was wondering the same thing. I bought an EZ wiring kit and found a spool of 16g cloth wire and wanted to wire everything under my hood in it. A lot of good info here.
...I'm glad that I'm not the only one who can learn something from time to time...was afraid you guys are gonna laugh at me
I grew up in the 50s. We were politer then and not so many noitalls. Promise yourself that you will repay the favor by not being a smart ass to your friends as they join the party in the future and you are the wise old sage.
A major consideration that has not been discussed is the fuse for the wire being used. The proper way to determine wire size is to calculate the total load on the circuit and the length of the wire, this data compared to the charts available on the net will give you the correct wire size. The fuse should be sized accordingly. Remember the fuse is to protect the wire in case of a short, to keep it from melting the insulation and starting a fire. The fuse does not protect the divice, fan motor, lights, etc as these are usually the cause of a short anyway.
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