12v LED replacement bulbs

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Ursula123

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Hi everyone, hope someone can help.
Firstly I'm no electrician but decided to replace all my standard 12v bayonet interior bulbs with LED's.
Simply they don't work, non of them in any of the fittings, put back standard bulbs and work ok.
The only thing I can think of is that with a multimeter I am getting 11.6 volts at the bulb contacts does that slight drop matter with LED's?
Did a little research and understand they differ from standard bulbs in that have poles, so tried them again in different positions still don't work
Is my problem that LED are so voltage sensitive, if so not much use, wouldn't want to be at anchor and suddenly lose my lights, was also thinking replacing nav bulbs, not so sure now. I did get them off Ebay they seemed much cheaper than at the swindlery, are they different?
Thanks for any input.
 
Hi, it is much more likely that the polarity is the wrong way for the LEDs. A normal lamp dose not care which way the wires go but the LED needs the +12v to go to the pin in the base and -12v to the outside of the can. This was the case with my LEDs on board. If you can find a junction box or where the lamp fitting is crimped to the boat wiring, change the wires over and try the LED again.

I hope that helps.
 
Ursula123 said:
Hi everyone, hope someone can help.
Firstly I'm no electrician but decided to replace all my standard 12v bayonet interior bulbs with LED's.
Simply they don't work, non of them in any of the fittings, put back standard bulbs and work ok.
The only thing I can think of is that with a multimeter I am getting 11.6 volts at the bulb contacts does that slight drop matter with LED's?
Did a little research and understand they differ from standard bulbs in that have poles, so tried them again in different positions still don't work
Is my problem that LED are so voltage sensitive, if so not much use, wouldn't want to be at anchor and suddenly lose my lights, was also thinking replacing nav bulbs, not so sure now. I did get them off Ebay they seemed much cheaper than at the swindlery, are they different?
Thanks for any input.
Click to expand...

Difficult to comment without knowing exactly what you bought. ... Got a link?

Obvious , stupid question .... are they the correct fitting? ... Usually double contact on a boat but single contact on a car ?

If they are double contact and have offset pins then they may be polarity sensitive. If they are single contact they may be polarity sensitive.

Id check one / them directly on the battery . I'd expect them to work on voltages down to about 10 volts but need to see the tech spec of the lamps you bought to be sure.

Quite apart from the non working LEDs you need to sort out why you only have 11.6 volts !
 
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I agree with the polarity suggestions. My mains charger failed recently and my domestic bank dropped to 11 volts, but the LED lights still worked.

As Vic says, a link to exactly what you purchased might help. I also agree with him that you need to investigate why you only have 11.6 volts.
 
You can test most "12v" LED bulbs with a 9v PP3 dry battery. You will probably have the pos/neg connections wrong way round for the bulbs.
 
Thanks for that, she's out of the water and I have been plugging her in and using eberspacher most times I'm on her, so maybe the charger isn't keeping up?
 
If the lamp you have is the middle one in the picture of three varients, then you have the wrong one. The two pins in your lampholder will be + and -, not + and +.
 
I wonder if you might possibly have bought the wrong type of 12v bulb. A quick search on the net brought up two different types of 12v, non-offset bayonet fittings: BA15D and BA15S, which differ in that there is a 90 degree rotation of the contacts relative to the locating pins.
Jeremy
 
myquest said:
If the lamp you have is the middle one in the picture of three varients, then you have the wrong one. The two pins in your lampholder will be + and -, not + and +.
Click to expand...

The listing states " BA15D/1142 (Parallel pins,double + contact)" so you are correct, these are the wrong lamps.
 
PaulRainbow said:
The listing states " BA15D/1142 (Parallel pins,double + contact)" so you are correct, these are the wrong lamps.
Click to expand...

Yep

Not obvious at first but they are the middle ones, labelled " Our bulb type ". It's the ones on the right that are required.

s-l500.jpg
 
I see that now thanks for your help, told you I was no electrician. Just bought the 12v bible I think I need more knowledge!!
 
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