Motorhome LED lights powered from Leisure Battery

Thread Starter

elskan

Joined Jun 1, 2016
6
Hi Guys

I have 2 LED interior lights to fit in my Motorhome.

They will NOT work from the cigarette lighter in the rear (Leisure Battery);
They will NOT work from the cab cigarette lighter (Van Battery);
They WILL light if connected directly to both batteries.

The engine is not running;
No charger is charging either battery.
12V IS available at both lighter sockets and the voltage (12.7) remains the same whether the light is connected or not.
Other accessories DO work from both sockets, eg phone chargers.

I have opened the plug and there are no electronics within.

Regards

a very frustrated Brian
 

bwilliams60

Joined Nov 18, 2012
1,350
Can you post a picture of the lights with the connector you are using. It sounds like you are not getting a good connection at the cigarette lighter so perhaps the male end is not mating with the socket properly?
 

AlbertHall

Joined Jun 4, 2014
10,572
Can you post a picture of the lights with the connector you are using. It sounds like you are not getting a good connection at the cigarette lighter so perhaps the male end is not mating with the socket properly?
Yes. Check whether the voltage actually appears at the plug connections or at the lights when plugged in.
 

Thread Starter

elskan

Joined Jun 1, 2016
6
UPDATE

A little more tracing and the problem lies within the cigarette lighter socket.

Hook on to the rear of the socket and all works. Connect to the inside of the socket and the light is dead. Still, 12V and other items still work.

The socket is a "Marine 12v power socket".

Brian
 

Thread Starter

elskan

Joined Jun 1, 2016
6
Thanks, guys, for the replies

I have opened a lighter plug and connected 2 wires (+ to center).
On the 2 wires I have full 12V.
On connecting these to 2 different LED lights (Lights as in LED strip) the lights do not work.
Move the power take off to the feed to the socket and all works.

I note there is a small signal LED on the plug which lights to show a good connection. However, I have introduced two probes into the socket that gives 12V but the lights do not work when connected to them.
 

bwilliams60

Joined Nov 18, 2012
1,350
I suspect you have a bad wire or a bad connection somewhere. An LED light by itself takes almost nothing in amperage to light. It is possible you are lacking sufficient amperage to illuminate your light due to damaged wiring or poor connections leading to the socket. Do you have an incandescent bulb or headlight you can try across the power and ground. That will tell you quickly if you have a problem. Voltage drop test?
 

Thread Starter

elskan

Joined Jun 1, 2016
6
Hi bwilliams60

Thanks for your help. I'm a little sad to say that an incandescent 21watt brake light works fine when connected to the two tails from the lighter plug. 2 different 12V LED lights do not work.

Interestingly a 36watt 12V fluorescent light does not work either.

Hence, since we have ruled out everything else, we are left with the socket OR the plug.

IT IS THE PLUG. I connected power directly to the plug with jumpers from the battery. Everything works on the plug's tails EXCEPT the LEDs and Fluorescent.

CONCLUSION Something within the plug interferes in some way with LED lighting. Perhaps that little red LED on the plug to say it is working.

BUT I have the same problem in the bathroom of the motorhome. 12V feed lights an incandescent bulb but NOT LED or Fluorescent.

What is it that interferes on a 12V supply, where I have both volts and amps, that blocks an LED working?

Regards

Brian
 
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