Circuit Breakers

8BA

8BA

Junior Member
I am starting to have some issues with the Customlines electrics and, as I do a far bit of night driving, will change to 12 volt as I have the replacement parts. Changing everything seems quite straight forward but the circuit breakers have me slightly puzzled.
If the 6 volt 15 and 30 amp have 12 volt sent through them, will it cut their amperage to 7.5 and 15 respectively?
Or am I guessing wrong?
Or should just replace the present 6 volt 15 and 30 amp circuit breakers with 12 volt similar?

Don
 
The circuit breakers will always have the same amp rating regardless of voltage. Your 30 amp breaker on 6v will be a 30 amp breaker on 12v...etc. Same as a 10A fuse is always 10A regardless of a 3v or 110 volts environment.

To make the voltage conversion you simply install breakers with half the present current as most devices like headlights are half the current on 12v as they were on 6v. But check anyway. Good news, you can take your existing 15 amp breaker and use it in the position the 30 amp is now in and buy a new 7.5 amp breaker for one now in the 15 amp position.

Out of curiosity, what 'issues with Customlines electrics' are you having which will disappear after the 12v conversion?
 
Paul,
I think it is simply the age of the electrics. The generator has not been charging properly for quite some time and i have had several occasions where the amps gauge suddenly went to full discharge whilst driving meaning a quick stop and disconnect battery. That turned out to be the Regulator sticking. The starter is definitely tired and this winter has made it quite well known that it is far from happy. It just won't do anything. I would'nt normally have changed over ( i have a 1947 Prefect which is still 6 volt positive and works very well) but I have the replacement parts so thought I might as well do it.
It's probably sacrilege but the 12 volt negative is somewhat more convenient even if the initial cost of parts was not due to virtually everything having to be sourced from dealers in the US with the subsequent price difference and postage.
But you have to deal with that if you insist on driving 60+ year old cars.
 
Don you have not mentioned what wattage 12 volt headlights you are going to fit. If QH lights are going in with a higher current draw then I would not worry to much about replacing your circuit breakers. But maybe a small fuse box added to protect some of your 12 volt items would be a good idea. Are you fitting a 12 volt alternator ? It might be a better option then a 12 volt generator and voltage regulator. Generator regulators seem to be a big problem for many people because they are difficult to repair and adjust correctly. Or hard to find someone to know how to do it. I know how, but im retired, or trying to be. Good luck, Regards, Kevin.
 
The circuit breaker ratings were used to protect the larger gauge conductor wires of the 6-volt system so as long as you don't change the wire gauge, those OEM type circuit breakers will work just fine. You can use lower ratings no problem as long as you don't use higher ratings that the wiring was designed for. Now if you add in new 12-volt accessories and use smaller gauge wiring then you will need to fuse those according to the wire gauge used. Kevin already touched on this in his post.

You will need something like a runtz voltage converter for your engine instrument gauges. You can use a dropping resistor but the runtz unit regulates the input voltage to each gauge better. The amp meter is likely an induction type so it should work OK like it is. All of the bulbs will have to be changed over to equivalent base type 12-volt bulbs. Switches should all work fine on any voltage you throw at them within the automotive spectrum. Solenoids can be hit or miss when changing voltage but 12-volt solenoids are available for most applications. 6-volt starters will run on 12-volt (a lot faster rpm) but a rebuild that includes 12-volt type fields would likely be more efficient and make it last longer.
 
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If going to 12v, you can use an inexpensive ceramic type voltage reducer for your heater motor. After fiddling unsatisfactory with various resistors I kept my 6v horn relay and horns .... they are seldom used and if used, are usually used n short bursts. If you have directionals, the flasher unit should be changed to a 12v unit.
 
I recently changed to an 8 volt battery. All the lights are now brighter, and it turns over like a 12 volt system
Cheers, Byron.
 
Byron Warwick said:
I recently changed to an 8 volt battery. All the lights are now brighter, and it turns over like a 12 volt system
Cheers, Byron.
Click to expand...

Two questions : 1. Did you adjust your voltage regulator to put out a high enough voltage level to keep that battery charged? 2. Do you enjoy changing light bulbs?
 
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