Looking for recommendations on fuse sizes for my 6-volt roadster. The wiring is all new and plenty big. I need fuses for the following. •Ignition •Head Lights •Brake Lights •Horn •Gas Gauge •Taillights Any help is appreciated! Chris
Depending on what headlight switch you are using will tell you what fuse is needed for the headlights. A lot of the headlight switches had circuit breakers integrated with the switch. As far as other fuses, I would just find an owners manual for a 6V car and go from there. The horn probably uses a 30 or 40 amp block fuse (metal can with two terminals).
it's a good idea to match the fuses to the wire size, since the job of a fuse is to protect the wire by melting itself instead of the wire melting. Voltage doesn't really matter for fuse size. But you do need heavier wire in a 6v system vs a 12v system because current is twice as high. 10 gage 30 amp 12 gage 20 amp 14 gage 15 amp 16 gage 10 amp
I went bigger than I needed to with the wiring, the smallest in the system is 12 gage for the gas gauge and sender. The rest is 10 gage and a couple of 8 gages. Not sure if it would be good idea to run a 20 amp fuse for the gas gauge?
You can run smaller fuses than the wire needs. Sounds like you went a bit overboard with the wire sizes....but it should work fine.
Need to know how many amps each item is pulling for fuse size. Eletrical systems should be design to handle at least 125% of maximum amperage. If you have head lamps that are 55 watts, they draw 4.58 amps (Example: 55 watts divided by 12 volts = 4.58 amps). Two headlights means 9.16 amps plus your added max percentage, should use no larger than a 15amp fuse for the headlights. Use to big of a fuse and things will start smoking before the fuse blows. Good luck!
Thanks I'm not 100 percent sure what the amp pull is for the individual components, lots of the stuff (ex. headlights) are NOS and didn't come with much info. I'm looking for general 6V recomendations.
THere were not many fuses in cars when 6v systems were being used....usually a breaker on the light switch was about it, maybe an inline fuse on the heater or radio, maybe a fuse on the headlight switch for the running lights/dash lights.
According to Ohm's Law (E=IR) a 12V system uses half the current (amps) of a 6V system to perform the same work. By this theory, your 12 volt fuses should be half the value of the 6 volt ones. Even if you have the heavier 6volt wiring, the smaller fuses will protect the component better, so there's no harm in a lower value fuse.
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