6 Volt Switches on 12 Volts

[Bob Riding]

I'm starting the rewiring of the '51 Suburban and although I have the original dash switches (instruments, headlight and wiper) I don't trust them to continue to work flawlessly after 73 years. My concern is if I purchase NOS switches from our vendors or eBay, will they be able to handle the voltage?  I will be running 12 volts.  Anyone find any modern replacements that would fit? 

Also- in the picture of the '51 headlight switch below, I assume the little gray box is a headlight relay?

[Sniper]

12v thru a 6v switch should not be an issue, the other way around though could be.

 

When I rewired my car I used 65ish Mustang switches as they fit the motif.  I'd post a link by I'll be darned if I can find the order.  But I got them from CJ Pony parts.

 

 

[Dave72dt]

I believe it to be a circuit breaker.

[Sam Buchanan]

27 minutes ago, Bob Riding said:

I'm starting the rewiring of the '51 Suburban and although I have the original dash switches (instruments, headlight and wiper) I don't trust them to continue to work flawlessly after 73 years. My concern is if I purchase NOS switches from our vendors or eBay, will they be able to handle the voltage?  I will be running 12 volts.  Anyone find any modern replacements that would fit? 

Also- in the picture of the '51 headlight switch below, I assume the little gray box is a headlight relay?

 

 

Your original wiring and components only need to carry half the current on 12v as they would on 6v, you are good to go! 

Edited December 10 by Sam Buchanan

[Bob Riding]

2 hours ago, Dave72dt said:

I believe it to be a circuit breaker.

Good call. That checks out- it's a 30amp breaker. I wonder if you can reset it if it trips?

[Bob Riding]

2 hours ago, Sniper said:

12v thru a 6v switch should not be an issue, the other way around though could be.

 

When I rewired my car I used 65ish Mustang switches as they fit the motif.  I'd post a link by I'll be darned if I can find the order.  But I got them from CJ Pony parts.

 

 

What about these guys? Heater fan switch on the left and defroster speed switch on the right, both with ceramic heat sinks. Would 12 volts cause less heat, due to halved current? The heater motor itself will be 12 volts.

[moparfun]

The breaker resets on its own.

[andyd]

My 1940 Dodge has been 12 volts, 318 poly etc since 1973 and I've used the stock headlight switch since with 12 volts thru it without an issue and a voltage resistor in the power circuit for the fuel gauge, also stock ignition switch and starter button(on dash as all RHD cars have), toggle switch is electric fan and black button is the windscreen washer, wipers use the stock toggle switch under the dash edge......so far after 51 yrs no problems........lol......andyd  

[Bob Riding]

30 minutes ago, andyd said:

My 1940 Dodge has been 12 volts, 318 poly etc since 1973 and I've used the stock headlight switch since with 12 volts thru it without an issue and a voltage resistor in the power circuit for the fuel gauge, also stock ignition switch and starter button(on dash as all RHD cars have), toggle switch is electric fan and black button is the windscreen washer, wipers use the stock toggle switch under the dash edge......so far after 51 yrs no problems........lol......andyd  

Funny- your dash is (of course) a reversed layout from my D14 coupe.😜 What about your defroster speed switch and heater fan switch? They both have the resistance elements which kinda spooks me.

[Sniper]

2 hours ago, Bob Riding said:

What about these guys? Heater fan switch on the left and defroster speed switch on the right, both with ceramic heat sinks. Would 12 volts cause less heat, due to halved current? The heater motor itself will be 12 volts.

 

They are wire wound resistors.

 

Twice the voltage means half the current and current flow is what causes the heat.  That all said, I put a 12v blower motor in my 51.  The old one's wiring had a bad case of insulation failure.

 

http://www.yourolddad.com/blower-motor

 

 

[andyd]

Bob.....you mentioned the Heater & defoster switches......here in Oz as far as I know a defoster was never available for mopars, at least pre war ones and a heater whilst available thru the dealer would have been an accessory style as far as I know........I ended up puting an English Smiths aftermarket heater/demister in the car but apart from turning it on to see if it works I've never really used it, those demister vents on the dash are ones that I found at a swap meet and again, whilst connected up have never really been used..........even in winter its generally 20C  or above........the heater/demister controls are mounted in the stock dash radio holes, the radio is mounted in a spare dash grille as a counldn't bring myself to actually cut up the newly rechromed one.....lol......looks o/k    

[Bob Riding]

6 hours ago, Sniper said:

 

They are wire wound resistors.

 

Twice the voltage means half the current and current flow is what causes the heat.  That all said, I put a 12v blower motor in my 51.  The old one's wiring had a bad case of insulation failure.

 

http://www.yourolddad.com/blower-motor

 

 

Thanks for the step by step - I followed your lead and also bought a 12 volt motor. My original wire wound resisters look OK- would you replace them with NOS (which are available) just to be safe?

[Bob Riding]

6 hours ago, andyd said:

Bob.....you mentioned the Heater & defoster switches......here in Oz as far as I know a defoster was never available for mopars, at least pre war ones and a heater whilst available thru the dealer would have been an accessory style as far as I know........I ended up puting an English Smiths aftermarket heater/demister in the car but apart from turning it on to see if it works I've never really used it, those demister vents on the dash are ones that I found at a swap meet and again, whilst connected up have never really been used..........even in winter its generally 20C  or above........the heater/demister controls are mounted in the stock dash radio holes, the radio is mounted in a spare dash grille as a counldn't bring myself to actually cut up the newly rechromed one.....lol......looks o/k    

Looks great, thanks!

 

[Sniper]

7 hours ago, Bob Riding said:

Thanks for the step by step - I followed your lead and also bought a 12 volt motor. My original wire wound resisters look OK- would you replace them with NOS (which are available) just to be safe?

 

I did not, but if the cost wasn't too much I probably would, just for peace of mind.