Head light wire size 16,14 or 12 awg

[Takid455]

car is 78 t/a w/ 16 awg wiring for the headlights. I plan to run sealed beam units with H4 & H1 bulbs. 55/100 and 100W respectively. Hella makes/ made these and are very nice. Cibie made a some too IIRC. anyhow, I know some of the H series bulbs can provide high output while drawing less current. This is most likely based on manufacture.

Wondering if I should go through the effort and make a new harness using thicker gauge wire or stay with the stock 16 awg harness. harness is in good shape.

what gauge do OEM use for HID and H series bulbs?

to protect the switch, I am running a relay on the high beam circuit.


Thoughts

[Bryce]

I found this

http://www.the12volt.com/info/recwirsz.asp

determine length and watts it will tell you the gauge

[TnBlkC230WZ]

It does depend on the lenght of the wire run as stated above. You will be pulling about 16amps with both headlights. If the relay is near the headlights, you can "get away" with 16 gauge, but I wouldn't use less than 14 guage for total circuit lenght up to 10 feet. this will keep your voltage drop at .83 volts or less. Over 10 feet, 12 gauge will limit your voltage drop.

I personally used 12 guage on my high beams with at total circuit length of about 8.5 feet.