LED Lamp Changeover Blowing Fuse

[GeorgeB]

Hello _ I recently made a decision to change a couple of incandescent reading lamps on my van's FWD light circuit (rated with 15 AMP Fuse). Only changing them as the originals (whilst working) were missing their tulip glass shades and can't seem to source replacements. So I bought a similar fit and form pair of 12V LED's off eBay. Wired one in, black to black other wire to switch (as per how the previous lamp was wired) and switched on the Internal Lights Master switch to here the fuse blow. Went and made a tea, came on here read up a bit here + elsewhere and one source mentioned possible issue with LED polarity being wrong, so swapped over wires (I'm using a WAGO connector) and it simply blew another fuse. All the time I leave the new LED lamp disconnected (wires open) and replace the fuse every other light still works as does the original. I've read that LED's can possibly have a power spike - could this be the issue (so need t review my fuse sizing) or is it the fact that mixing incandescents (in parallel) with LED's causes an issue? Not in the mood for stripping out any wires yet as the weather is not good, so just making a mess every time I get in and out of van. My logic says it is an issue with the new LED lamp - any ideas please?

 

[pappajohn]

Sounds like that led has an internal dead short.
It would normally use less than 1 amp but is popping a 15 amp fuse.
If it's polarity sensitive and wire the wrong way it simply won't work, that won't cause a blown fuse.
Voltage spikes will affect the lamp, not the wiring.
Can you try another led.

 

[DBK]

How are you connecting the LEDs? I suggest connecting directly to a stand alone 12 volt battery to see if they actually work. Don't permanently connect them, just touch the wires to the terminals. There shouldn't be any sparks.

A photo of the original bulbs might help, just in case they aren't 12 volt.

 

[GeorgeB]

I can - one other to try. Bear in mind I bought these "switched stalk/flexi lamps" off eBay so they might both just be poor quality. I'll try and report back once my wife is back with a box of new fuses.

 

[The Wino]

Sounds Very odd we've changed quite a few over the years the worst that happens usually is some wont work if the polarity is reversed sounds like a short somewhere. It sounds daft but are the wago connectors separate for the two wires some of them look like they are connecting separate wires but actually join them together ( can't quite explain it without a picture!)

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[pappajohn]

If the fuse doesn't blow when the bulb is removed there's nothing amiss with the wiring.

 

[GeorgeB]

How are you connecting the LEDs? I suggest connecting directly to a stand alone 12 volt battery to see if they actually work. Don't permanently connect them, just touch the wires to the terminals. There shouldn't be any sparks.

A photo of the original bulbs might help, just in case they aren't 12 volt.

Ha........after jury rigging up some long wires to reach across terminal easier neither of the new LEDs work across my Stag 12V battery, so it looks like I am victim of the supply chain of a country that shall remain un-named - wouldn't want to be bombarded with unwanted virus or malware. The original is a 12V lucas type bulb, fairly common with 2 strand connectors. I just wish I could find a supplier of incandescent stalk lights and do a full interchange of fit, form and function.

 

[GeorgeB]

Fuse replaced and just checked all the wiring to the disconnected ends now with the replacement LED light removed and getting 14.29 volts which makes sense to me on a healthy leisure batteries (I've got 2). I'm assuming this isn't too high and input voltage or had an impact on the LED, but regardless they don't work. Got to source some new lights now. Thanks all for very quick support.

 

[headlight]

Fuse replaced and just checked all the wiring to the disconnected ends now with the replacement LED light removed and getting 14.29 volts which makes sense to me on a healthy leisure batteries (I've got 2). I'm assuming this isn't too high and input voltage or had an impact on the LED, but regardless they don't work. Got to source some new lights now. Thanks all for very quick support.

You should be getting about 12.7v - 12.8v from a fully charged lead acid leisure battery not 14.29v, unless the battery was being charged, solar, engine alternator or plugged in to EHU.
What was giving you the 14.29v reading, a multimeter ?
If the leisure batteries were not being charged at the time and the reading was from a multimeter check/change the multimeter battery as when their batteries are low they tend to read high.
Have a look on Aten Lighting website for replacement led's.
I have 13 internal lights and changed 6 at first leaving 7 incandescent bulbs in place and they all worked fine even though they were mixed.
Later I swapped the remaining 7 incandescent for led's.

 

[pappajohn]

Did you try the wires with both polarities.
It sounds like the led's were cheap Chinese tat.
Many are not capable of running at a higher voltage than 12v.....more expensive ones are capable of a wide voltage range......maybe 10v to 19v.
Buy quality, buy once.

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[scotzsue]

Did as headlight with first van. Changed half, i didn't buy enough, then changed the others when i had more supplies. Bought first lot at Peterborough show and the rest at O'Leary's