Led navigation lghts

[General Zod]

Can some tell me why do LEDs (navigation lights) take a bigger fuse eg 10 amps. I just changed from the old navigation lights which used bulbs and a (5amp fuse) to new led navigation lights. ( not just the bulbs i changed the whole setup.) The LEDs burnt the 5amp fuse 3 times, I checked to see if I had wired it wrong but that was ok, I changed to 10 amp fuse and all is ok now. But why do the LEDs take 10 amp fuse? I throught they were suppose to draw less current or amps what ever it's called. I'm I using more power now? Very puzzled please explain.

[Testlab]

You have a problem. They definitely should not draw over 5 amps, in fact they should be less than 0.5A. Check your wiring for shorts or some other load connected to the same circuit. If you've an aluminum hull then check for shorts to the hull too.

Unlike regular incandescent bulbs which will not glow if there is a short in the cabling, LEDs will light up with surprising little voltage and current, especially if the short is at the far end of the cable and the wire is fairly thin.

[General Zod]

You have a problem. They definitely should not draw over 5 amps, in fact they should be less than 0.5A. Check your wiring for shorts or some other load connected to the same circuit. If you've an aluminum hull then check for shorts to the hull too.

Unlike regular incandescent bulbs which will not glow if there is a short in the cabling, LEDs will light up with surprising little voltage and current, especially if the short is at the far end of the cable and the wire is fairly thin.

Thanks, yes they are connected to some other load. Looks like I have to find out to which other load. But what well happen if I leave it. Well it draw more power? or just need that better fuse. The old incandescent bulbs didnt short circuit or anything like that, they all worked fine. I have a fibreglass boat.

Thanks in advance.

[Testlab]

The problem with leaving it is you could wind up with a fire. You need to check the other load, or at least disconnect the new lights and see if the 5A fuse still blows. When you do check the wires going into the lights for correct polarity (red is positive) and look for cuts or breaks in the insulation. Make sure your mounting screws haven't pierced other wires behind the mounting location.

I cant think what other loads would be connected to the navigation lights. Usually you have the nav lights on one switch, the anchor light on another (or a split or two-way switch does both) and separate switches for everything else. I have seen instrument lights and compasses wired to nav lights but they should be a low load.

By the way, to get wattage, multiply together volts and amps. So if you know you have 3 x 4W globes then you have 12W load or 1A on a 12 V system.

Can you post a link to the LEDs you bought or send it to me by pm? I will check the specs. It is remotely possible they do not have the dropping resistors built in or they are for series connection.

[General Zod]

The problem with leaving it is you could wind up with a fire. You need to check the other load, or at least disconnect the new lights and see if the 5A fuse still blows. When you do check the wires going into the lights for correct polarity (red is positive) and look for cuts or breaks in the insulation. Make sure your mounting screws haven't pierced other wires behind the mounting location.

I cant think what other loads would be connected to the navigation lights. Usually you have the nav lights on one switch, the anchor light on another (or a split or two-way switch does both) and separate switches for everything else. I have seen instrument lights and compasses wired to nav lights but they should be a low load.

By the way, to get wattage, multiply together volts and amps. So if you know you have 3 x 4W globes then you have 12W load or 1A on a 12 V system.

Can you post a link to the LEDs you bought or send it to me by pm? I will check the specs. It is remotely possible they do not have the dropping resistors built in or they are for series connection.

lights and the type of switch panel and pm sent

Edited November 15, 2012 by General Zod

[Testlab]

Well I can't see any reason why they would blow a 5A fuse. I sent you a couple of messages but not sure if the message system works from my iPad. I will pop into the supplier you mentioned and have a look, but can you also check the blown fuse is definitely 5A and not 0.5A or 500mA?

Btw, nice setup, very neat.

Edited November 14, 2012 by Testlab