12 volt wiring for lights

[pontoon chief]

I am attempting to install six 12 volt lights in a boat.The bulbs are 12 volt #1156 single filament bulbs.I ran a black wire to all lights and then to the ground side of the master switch wire block.I then ran a white wire to the 6 lights and then put a 30 amp fuse into the line and than I put a 3 pole switch with a Ground pole,a power pole and a load pole in the line and than ran a wire to the positive side of the master wiring block.
When I placed the positive wire on the positive side of the switch and turned on the switch,the fuse block smoked and then popped.I than put the positive wire on the load pole of the switch and again the fuse popped.

Am I doing something incorrect,if so what.

Thanks,
Patrick

 

[bjcsc]

Re: 12 volt wiring for lights

What kind of switch is it? I doubt it is a 3-pole switch. My guess would be that it is a single pole double throw switch, in which case the ground does not belong. Can you post a picture of the switch, or a link to it from were you got it? If you can show me the switch I can tell you how it should be wired...

 

[Bondo]

Re: 12 volt wiring for lights

It Sounds like you're trying to wire 12Vs like you wire 120Vs,........

It Can't be Done That Way......

 

[imported_Curmudgeon]

Re: 12 volt wiring for lights

Red wire from fuse block to center of switch, red wire from bottom of switch to positive side of lights, black wire from negative side of lights to battery ground.

Only two wires involved with DC .. positive and negative.

 

[Boatin Bob]

Re: 12 volt wiring for lights

It's very possible pontoon could have a switch with a ground pole on it if it's got an indicator light inside, it's needs a ground for the light however without knowing exactly what type of switch he has we are all guessing in the dark.

 

[Mark42]

Re: 12 volt wiring for lights

The 1156 should work, just pack with marine grease or dielectric grease to reduce corrosion of the socket if used ouside.

Also, tinned wire lasts longer in a marine environment.

Use a continuity tester to figure out where the circuit is grounding.

And you do connect them in parallel, just like house wiring.

 

[pontoon chief]

Re: 12 volt wiring for lights

I can not link to a photo of the switch,but it is made by Conduct-Tite #84894 and is described as Red LED metal toggle 30 amps.
There is a small light at the end of the toggle lever.
The diagram provided on the back of the package shows the top post being Positive,the bottom post being the Ground,and the middle post being Accessory.
It is a On or Off type switch with only the two positions.
Maybe this can help.

 

[Boatin Bob]

Re: 12 volt wiring for lights

OK so try leaving the ground wire off the switch for now and try it again, it's possible you could have a defective switch shorting out internally.

 

[bjcsc]

Re: 12 volt wiring for lights

OK, so I am guessing it is similar to these?

If so, this is how I would wire it:

Additionally, the wattage of your 1156 bulbs is unknown. I suspect they are 21w, but they could be 50's. Only you know. If 21w, then you're only drawing ~10A. You could use 18ga wire (minimum) and a 15amp fuse. If 50w you're drawing ~23A. You could use 14ga wire (minimum) and a 30A fuse. Good luck.

 

[pontoon chief]

Re: 12 volt wiring for lights

bjcsc,you are the man.That is exactly what I have,and the diagram you provided is exactly what I was looking for.
Many thanks,
Parrick

 

[bjcsc]

Re: 12 volt wiring for lights

No troubles. Just remember that the fuse is designed to protect the wires, i.e. make sure the fuse you use matches the capacity of the wire you use and does not exceed it. (The fuse can be less than the wire's capacity, but not greater than it) In general, with normal wire runs: 10A for 20ga., 15A for 18ga., 20A for 16ga, 30A for 14ga., 40A for 12ga., and 50A for 10ga..

 

[jlinder]

Re: 12 volt wiring for lights

The bulbs you are using are rated for 26.9 watts. This gives a little over 2 amps each or about 12-13 amps total.

When you fuse you need the fuse to be no larger than the current capacity of the smallest component in the circuit.

I suspect you have one wire from the switch then the wire goes from bulb to bulb and at each bulb you splice on. If that is the case you need to run 14 ga wire (it is rated for 15 amps) and use a 15 amp fuse. However, that is a little close and you might want to run 12 ga and a 20 amp fuse.

Another thought is to go to LED bulbs instead of old incandescent bulbs. They draw almost no power so you can wire with 18 ga with no problem, last forever, but most importantly since they draw such little power you can leave them on for long periods of time and not kill the battery. (You don't want to draw 12 amps for hours and hours).

Don't know your specific application, but I used amber trailer clearance lights for a nice soft amber glow. Keeps bugs off and I can run the lights all night (less than 1 watt per lamp or less than 1 amp total draw).