Wire sizing questions

[Rick Parker]

I'm doing some rewiring and wondered what size (gauge) the wires from the circut breaker to the starter solenoid & Amp gauge are on an ERA? And is 18 gauge heavy enough for the headlights?

Thanks.........Rick

[Bob Putnam]

We use 10 gage wire in the main power circuits.
16 gage to each headlight, with a 14 gage feed through the switch to the fuse.

On a car with more current drain and a big alternator - like a late model FI setup, 8 gage primary would be appropriate.

[Rick Parker]

Bob:
On a carbureted engine with MSD, Spal fan (24 amps??)and normal lights an no other accessories is a 40 amp circut breaker heavy enough, seems too light IMO. I had thought of attaching the heavy power lead for the MSD directly to the starter (power lead) and bypass the circut breaker on that item but it still seems like the circut breaker needs to be of a higher capacity? Am I overlooking something basic?

Thanks...........Rick

[weekendwarrior]

Look at this site. Info on correct 12v wire sizing. Wire is heavier than SAE but in tech section explains the diff.

http://www.ancorproducts.com/

They have the heavy duty fuses as well.

Regards

[Rick Parker]

Bob :

Do you mean two individual 16 gage wires to each headlight, one for high beams (fuse 7) & one for low beams (fuse 8) each originating from the fuse panel? Or 1 wire for high beams shared by both headlights, and another wire for low beams shared by both headlights?

Thanks for your help

Rick

[Bob Putnam]

Rick,

We use a 50A circuit breaker (and this covers all circuits) without a problem. 40A is probably marginal, especially after it gets tired.

We use a separate 16G wire to each headlight - good for about 100W each. 18G would be OK if our customers would stay with a standard 35W/45W bulb, but they can't be trusted.