How 12v lights work?

[alexey75]

I have an issue with led awning lights blowing the fuse, I am troubleshooting it and have a general question.

When the trailer connected to shore power, do 12v lights get the power from the battery (and converter charges it in the background), or do they get the power from 110v through some converter?

[mr_andyj]

JRscooby wrote:
Part of my test kit is a 2-prong turn-signal flasher with jumper wires attached. Hook it in place of fuse, will work as auto reset circuit breaker. Then you can follow the wires with non-contact amp meter. When you pass the short the needle will stop jumping.

Laughing. haha. So simple, but so genius.... I will have to add that to my kit one day.

[JRscooby]

cockroach wrote:
I know this is basically an LED question but I thought it worth mentioning that an incandescent light does not care whether it is AC or DC. It will work on either.

While true you are overlooking most DC lamps are designed for low voltage. Put 120 to a 12 volt bulb and AC/DC will not matter.

[cockroach]

I know this is basically an LED question but I thought it worth mentioning that an incandescent light does not care whether it is AC or DC. It will work on either.

[wnjj]

Is the switch one with a light in it by chance? If it is, it wouldn’t hurt to pull the ground wire from it in case the short is within the switch itself. For that matter you can disconnect the output wire and then turn the switch on to confirm the fuse stays intact.

[Old-Biscuit]

bucky wrote:
The OP stated that he had unplugged the awning lights and the fuse still blew.

"I inspected and disconnected the awning lights, checked the cable that goes inside, checked the switch, all good, but still it blows the fuse."

YEP^^^^

So issue/short is between switch for awning lights and the wiring up to the connector for the awning lights

Run new wire from switch to connector

[bucky]

The OP stated that he had unplugged the awning lights and the fuse still blew.

"I inspected and disconnected the awning lights, checked the cable that goes inside, checked the switch, all good, but still it blows the fuse."

[mr_andyj]

dip some water out of a bucket and the water comes from the bucket.
Run a hose into the bucket and dip some water out of the bucket and now where does the water come from, the bucket or the hose? Hard to answer, same with the battery/charger combo. It comes from where it is connected to. It is all connected together.

In your case, no the AC is never part of the DC circuit other than the charger runs off AC power.

Sounds like you blow a fuse on just battery as well as with the charger/converter on.
I think the question got unnecessarily confusing.
LEDs must be bad (not sure how), or a short in the wiring. More likely the short is at a connection more than where a wire might have gotten damaged. Check connections first.
Check that the LED lights work. Connect them directly to a 12 volt power source and see if they work. Connect a fuse inline and see if it still works.
If all is good then you probably do have a short.
Finding electrical issues like shorts is not fun and not easy. There is no good answer at this point.

[poppa]

your led's awning lights are bad

[RickLight]

Where the wire come out of the wall is the most likely place for the wire to have damaged insulation.

[alexey75]

MitchF150 wrote:
Sounds like you have a short in the awning wiring? I assume it does this whether you are on just battery or 120v?

And it's just the awning light that blows the fuse either way?

Turn on your inside lights on and no problem?

Turn on your awning light and it blows the fuse?

Or a combo of both?

Not sure how you test that, but you gotta somehow take the internal wiring out of the equation with some test wires to see if it's the fixture or the wiring?

Good luck! Mitch

Yes, it doesn’t matter if I am on battery or 120v. I thought the problem with led connector, so I disconnected the led, turned on the switch and it blow the fuse...

Yes, it's just the awning light that blows the fuse.

No issues with internal lights.

Unfortunately I don’t have such long wires... I thought about it, connect one side to led and another side to the panel.

[RickLight]

Water in the awning lights is real possibility. So is a short in the LED strip itself.

If the LED strip has a plug on the end it would be a convenient place to test. If its soldered on then thing are harder. How are your electronics skills?

[alexey75]

2oldman wrote:

alexey75 wrote:
From the awning into the wall.

and this 'wall' is a 12v socket?

No, it goes through the wall and connects to the panel.

[JRscooby]

Part of my test kit is a 2-prong turn-signal flasher with jumper wires attached. Hook it in place of fuse, will work as auto reset circuit breaker. Then you can follow the wires with non-contact amp meter. When you pass the short the needle will stop jumping.

[time2roll]

If the fuse opens when you turn on the switch.... the trouble is after the switch. Probably a bare, cut or frayed wire is shorting to ground between the switch and the lamps.

Did this ever work? Or is this part of a new installation?