Check Number Plate Light (electrics question) draining
 

Hi All,
I had the "check number plate light" and a bulb had blown (it was black)
I decided to connect the multimeter to the plug that runs the lights and
the tailgate latch/lock after the X5 went into sleep mode,
the multimeter gave a reading of 3.41 volts in sleep mode!

Am I right in thinking that this voltage if anything should be in the
milliamp`s range and the voltage is an excessive draw? and this could
possibly be the culprit of my dreaded battery drain :dunno:

I did take out the dvd player in the boot and got longer than usual
from the battery before it died again.

Any help/info is greatly appreciated guys

What year, engine and mileage is you X? How old is your battery?

do you have tow package installed? if you do, is it the OE package?

(2003 had it for 2 years, 3.0i, 69k), this battery is 7 weeks old, both battery and alternator have been checked by the AA in the UK and both got a clean bill of health less than a week ago when I had to call out the AA to get a jump start in a hospital carpark :yikes:

just a guess, trying to brainstorm the issue

which lic plate light was it - left or right? the thing is, one of the lights is feeding to the trailer lighting and the trailer lighting is known to cold monitor the circuitry even when the car is long asleep - there was a post somewhere here on the forum about the trailer lights blinking - the LED lights actually visible, while old fashion halogen lights were being dark...

so, maybe you have measured the Pulse Width Modulation signal from the LCM at the 3 V?

Was your X leaving you stranded with the old battery or did this start after the battery was replaced? FYI---It would be important to know if AAA did a load test on the new battery. Quality brand battery?

Thans guys for the replies;)

No tow package installed!
Needed jump starts with all batteries I have put in the X5 (this one is the newest at 7 weeks old)
AA hooked up a hand held computer to the battery and gave me
a print out but I binned the print out, mechanic said nothing wrong with
alt or battery!

The present battery is actually an AA battery I got 7 weeks ago new.
I cant remember the battery specs off-hand 650-700 cold crank
I took a photo of the voltage! difficult whilst holding neg lead to an
earth (exhaust) pos lead to plug, multimeter and a cell phone to take
the photo. lol
originally reading 4.5v dropping 3.42v after two hours in sleep mode.

The new battery is a pip squeak. If you drive a fair amount of short distances, especially at night with the air conditioning running that battery is trying to sprint 26 miles. Class of battery should be 49 or H8. cold cranking amps should be 850 with 950 cranking amps. Should have 100 reserve minutes.

The tailgate latch works when the doors are unlocked. It that was the case when you checked the plug I would think it would show some current flow.

Oopsie, forgot your X is 3.0. In that case cold cranking amps only need to be 640 with 140 cranking amps.

Hi,
doors were locked and alarm on, the voltage is 2 hours into sleep mode,
this is volts (3.5v to 4.6v) I would think it should be if anything in Milli Amps

Thanks