Hot Rods Headlight Relay switch

I changed my 6 volt system to 12 volt in my '46 Ford. Do I need a relay installed in between my headlight switch and my foot switch?
Someone told me 12 volts directly to the headlight switch is too hot. Just getting someone's opinion.
Thanks, Mike

 

The 12V lights draw less current than the 6V, so if your switch is in good condition, it'll work fine. Unless you have some high-wattage off-road lights, but even then the switch may be adequate.

 

Even on new installations, be extra careful to ensure good grounds on the high amp stuff. That always seems to be where my electrical issues bite me in the ass. An extra ground wire to headlights is cheap insurance and only adds a black wire here and there.

 

I would say use a relay if you're going to have high current lights (like Halogen) or you're looking to save a old headlight switch that's expensive to replace.

 

When it comes to voltage it's mostly a matter of the insulation and distance between metal parts to be good enough to handle it, and if something is good enough for 6V it's most likely gonna be fine with 12 too, and probably a fair bit more than that.
Current is a different matter, more current causes more heat and can damage things sooner or later. However, if the lamps are the same power (watts) on 12V as on 6V they only use half the current, so the situation actually improves. If you have changed to higher power lamps the situation may be different.

Another thing is the actual condition of the switches. At 80 years old they may have seen a lot of use and wear, not to mention corrosion, so taking the main load off them and running the power to the lights through a relay may not be a bad idea anyway.

So, do you NEED to use relays? Almost never. Do you WANT to? I often do, you may or may not.