The Stovebolt Site Forums The Shop Area The Electrical Bay Differance between 6v & 12v light switch

I am finally converting my 1946 3/4 ton Chevy Pickup over to 12 volt and I am trying to figure out if I need to replace my 6v light switch with a 12 v one and why...it seems to me a switch is a switch...unless it has a fuse in it. Any thought here?

you're right, the switch will be fine on 12V, there's no fuse IN it, and if there's one ON it, it'll be OK because 12V means lower amps

Bill

The dimmer may not work quite the same. Personally I don't dim the dash lights.

Switch rating 101. Low volts (6) equal high current to do same work. High volts (12) equal less current to do same work. Dimmer is a resistor. To dim dash lights add resistance to the circuit. Here is where we get confused. In the best of all possible worlds you would keep the switch contacts from a 6 volt for all applications. Enough current for 6 volts and a good long, as in forever, life at 12 volts. The resistor to dim the dash lights would be matched for 6 or 12 volts. Bigger resistor for 12 volts and smaller resistor for 6 volts. So I suspect the manufactures, and this just my own suspicion, make one switch with different resistors for either 6 or 12 volts. I would expect the same for Heater controls as well. And like truckernix I don't dim my dash lights either. Any one take one apart to see if they are different?

Thank you all for your information...This forum is why I am a stovebolter.

Generally switches, like any electrical device, are rated for the amperage (heat) they can handle. 6v items carry twice the amperage as do 12v items of the same wattage. Therefore all your switch connections will handle 12v just fine given the same load (watts). Only if you increase the 12v wattage consumption (such as a stereo or amp) to over double the original consumption will you overload your original switch or wire. The formula is simple as pie P=IxE

Wattage(P) = Amps (I) times Volts(E)
24 watt taillight = 6 volts times 4 amps
24 watt taillight = 12 volts times 2 amps

If you are considering fixed resistance the opposite applies. Amps will double with voltage.

Sorry if this reply is winded.

For those not comfortable with electricity. I have found this to be helpful: Think water! OK, now, Volts is like pressure. Current is like volume. Resistance is like a kinked hose. Little kink is like a small resistor, tighter kink is like a bigger resistor. Watts? Like how much work can be done. Big hose=big volume=big wire and of course a little AWG number. Little hose= little wire and a big AWG number. AWG? American Wire Gauge. Current and Amps are the same thing. And yes all these things are related to each other. That is why the P=I times E thing works. P is Watts is work. I is current is amps is volume. E is Volts is pressure. And if you need to know E is "electromotive" force. Is this helpful? Smile and enjoy. Some one will want to talk about BMEP and Volume metric efficiency some day soon. Then some one else will have the information and I will get to listen.

Man, I can't even understand how water works. I pay the electric bill because they send the bill. I never see the electricity. What am I paying it for? It does hurt when you touch it though.