The Stovebolt Site Forums The Shop Area The Electrical Bay 12v ignition switch in 6v system

I cannot locally locate a 6 volt ignition switch for my 2nd series '47 chevy truck. I am keeping the 6 volt system with the floor start and was curious if using a 12 volt switch will harm anything? After all i am just completing a circuit right?

You're apparently not using a stock switch so it's hard to tell how it was made inside but generally speaking 12v systems carry half the current that a 6v system does. Moving to 12v meant that the wiring, contacts etc., could be made lighter gauge (read less copper and brass, less money).
Taint that much money for the proper ignition switch, that's the way I would go.
Denny Graham
Sandwich, IL

I checked at grumpys truck parts and they did not have a 6v switch. Does anyone know where i can get a 6v switch? I would like to keep it as original with a daily driver kept in mind.

try here, IGS47

Bill

'Taint no such animal Bill. You been smoking that weird stuff again.

Thank you bill. I have a 6v switch on back order, with the gm key.

A switch is a switch. There's no 6V or 12V to it.

Also, changing parts is not keeping it original. Original is the parts that were originally on the truck, not replacements.

Really? I thought 6v switches needed to have heavier guage wiring due to the higher amps.

there is no "wireing" inside the switch Dave, but yes, switches designed for 6V will have heavier moving and stationary contacts as Denny points out - whether you can find recently manufactured items that actually have is another storey .... I've been using a 6V application dimmer switch for a 120V pump motor on/off application for 30 years, the first couple [leftovers from my collection] lasted quite a few years, lately I'm lucky to get more than one season per switch .... don't tell the electrical inspector

Bill

I'll bet you're drawing a bunch of current thru that switch with that 120v pump motor, right Bill? You're probably getting a lot of arc-over when you trip the switch also. That means you've got the worst of both worlds when it comes to the life of a switch, ie., high current, higher voltage and no place for the arc to go, might try a cap across the switch?
Denny Graham
Sandwich, IL

the pump isn't too bad, about 6 amps, it's the arc mostly, that switch can click 100 times a day or more, but with the 2 poles I can fry one side and just shift wires to the other they're cheap enough from the local NAPA, where they know me well so they're just an 'expendable' .... I did try one from the TF era, but found it didn't hold up as well as the new 6V ones, so even the repro 6V must have better contacts

Bill

Provided the switch has the rated ampacity then you can use ANY voltage rating higher than you system. Pick a number any number 50 500 5000 volt PROVIDED it will carry the current
AND has the correct interrupt rating. IF a DC switch then if the two are adhered to then you are OK.

Sorta like fuses. There again you must have one rated at system voltage or above.

Dan Bentler

You are absolutely correct Dan, but generally speaking with the automotive electrical systems the 12v systems are carrying about half the current that the 6v systems do. This was one of the main reasons they moved to 12v in the 50's, ie., to save on materials like copper wire and brass contacts. The automobile industry has earned the reputation since the beginning of reducing costs as much as possible and less material meant less cost to build. There’s a big difference between the 6v & 12v lighting and heater wiring and switches.
Another good example that comes to mind is in the aviation and transport industries where higher voltages like 24v and 32v are seen often.
Denny Graham
Sandwich, IL

Denny

I did say correct current rating I believe. That applies to any piece of electrical equipment.

I am just an electrician but I do understand that doubling the voltage doubles the current
AND it quadruples the power for CONSTANT resistance.

Except for 3 phase and many single phase motors where if you connect for 460 you have half the current and if you reconnect same motor for 230 you have double the current. Power remains the same. 115 and 230 are more common on single phase.

Dan Bentler

Come on Dan, don't be so sensitive, this is a discussion forum not an argument forum like some of the others. No one is questioning your judgment or experience, I'm sure you're an excellent electrician.
We have a lot of young inexperienced new guys joining in all the time who never heard of Ohm's law, so often replies are made with them in mind. Basic point we were trying to get across is that in 12v automotive applications the components and circuitry are usually lighter duty.
Denny Graham
Sandwich, IL

Has anyone found a key start 6 volt ignition switch that will fit and can be used in the AD trucks? I would like to use the starter from a 52 car which does not use the mechanical 'mash' starter button.

I have one from a 58 TF (12 volt) but it would require dash modification.

TIA

Call Classic Parts about this key-start switch - be sure it fits in the dash of your-year A-D truck.

Thanks Tim.

It would be nice if the throat was the same size as the original, could be held in place through the original holder, and be flush with the dash.

I know. A tall order. But I can dream.

I will check into it.

Thanks again

Another good place to try http://www.dansclassic.com/