Gen 3 battery draining

I have a 2013 Jimny with a new battery.  Following a charge to 100%, the battery is running flat after about 10 days whilst parked and not in use. There is a 420mA current being drawn in the lighting circuit when the key is out and the doors are closed.  All the lights are working correctly and off during the current measurement.  Suspecting a faulty brake-light switch, I tried removing the fuse for the brake lights, but the current draw is the same.  Does anyone have a circuit / wiring diagram for a generation 3 or any suggestions about where to look next?  Does any other electrical system draw power from the light ring?  Thank you in advance.

Do you have an aftermarket stereo, alarm, tracker or other device fitted? Aftermarket stereos are often the cause

How do you know it’s in the lighting circuit? Did you put a current meter in place of the fuse or in the battery lead? Was the door open at the time?

Sub 50mA is more typical, but an aftermarket stereo, alarm or tracker can easily draw this amount of current.

Robin

Does it have a trailer socket or the remnants of such probably behind the rear passenger trim in the inner wheel skin?

Lambert wrote:

Does it have a trailer socket or the remnants of such probably behind the rear passenger trim in the inner wheel skin?

I think Lambert is on to something.  Trailer wiring is more exposed and prone to damage than most car circuits, and it has relays as well.

A relay can fail in such a way that it becomes a constant power drain, effectively a resistor.  This is not uncommon after years of service, particularly if the relay is exposed to damp.  One way to check for a short is to disconnect each relay one by one while monitoring the draw at the battery.  

Good luck!

Hello Robin,

Thank you for your reply -  it is greatly appreciated.  The 50A lighting fuse was removed from the fuse box in the engine compartment and a current measured with a meter inserted in series, whilst the doors were closed.  The car doesn't have any aftermarket additions, but I do not know its full history.  When the doors were opened, the current draw rose to 950mA, but the cabin light did not illuminate. I will take a close look at the radio as you have suggested. Something on the light-ring is the culprit. 

Thanks again. 

Kind regards, Mark.

Thank you for your suggestion Lambert - in all honesty, I do not know. I will take a look when I next get a chance. Much obliged.