12 volt spotlight repairs

SteveGorst

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At the end of last season I broke the toggle switch on my waterproof hand held 12 volt spotlight. A couple of weeks ago I took it apart to see if it was repairable and it looked like a simple job of replacing the switch with a standard toggle switch from Maplins together with a waterproof cover. Last week I carried out repairs with a new toggle switch and cover, bish bash bosh job done. Or so I thought.....

Today I connected it up to the boat and found that the torch got extremely hot and black whispy things were being produced and floating around in the lense.

Anybody got any idea what can be happening. The job is obviously more complicated than I first thought, there must have been something extra in the switch that I replaced.
 
I'd have though it was a simple job of replacing the switch with one from Maplins.

Anything special about the old switch that you can see? Photos?

New switch was adequately rated for the job? Possibly not if you are talking about a 10 zillion candelpower lantern and a Maplins switch

Assembled with the wiring touching the bulb and therefore being burnt?

Did it work?

Torch getting hot though ... problem there somewhere.
 
yes the torch worked but I'm not sure for how long it would have carried on working. I did check out the rating of the switch as it was one of the zillion candela type that could light up a buoy at a ridiculous distance, I think he said it was rated to 4 or 5 amps.
I have no pictures of the old switch as it was chucked away but I do wonder whether it had a resistor or something in it to reduce the voltage reaching the filament. The black whispy things seem to be getting produced by the wire supporting the filament. I don't know what you call this.
 
The lamp was probably on the way out anyway. This could be what damaged the switch. It is extremely unlikely that there was a dropping resistor, or anything similar as this would have to be rated to the same power as the lamp to drop the voltage to 6v for example.

Replacing the switch as you did was correct, I would think that if you replace the lamp that everything should be OK.
A typical spotlamp can have a lamp form 50 to 150w. Many use agricultural lamps or lamps fitted to construction vehicles.
 
Thanks for your comments, the switch didn't burn out it was damaged physically and the toggle broken off.

I think I'll take it apart again tomorrow and run it while it is apart and look for a short. I'll take some pictures of it if it isn't working as I don't think it has a removable bulb it seems to be all built in. It came with the boat when I bought it so I don't know how old it is, or the model etc. It could be time to buy a new one but it's a bit frustrating as it seemed such a simple repair.

We need more to work on don't we.... Photos will follow tomorrow.

Cheers
Steve
 
ah sorry - I"d try a new hook up as close to the lamp as possible, should asertain wether it's a duff lamp or dodgy wiring leading to it... Possible you've snagged a wire while fitting the new switch.
 
Has the lens started to cover with white smoke ?
If it has it is probably a damaged filament
Is the lamp a 'sealed beam unit' ?
 
I think you could describe it as that and like I said it has bits of whispy stuff coming off the filament and floating around inside the lens. It's all a bit weird.

Cheers
Steve
 
Just a thought. Many of the switches from most supplyers today are ac not dc and from your description assuming that you have not a fault elsewhere then this is the probable cause.
 
Re: 12 volt spotlight

I have a Nightsearcher handheld gathering dust since fitting a permanent spotlight. It's megapower, rechargeable AND 12v supply. Good review in PBO.
Cost £25. Interested?
 
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