Parasitic electrical drain

[X5smw]

Hi all… what’s the best way to locate a power drain? 
 

basically, I have changed the boot on the x5 and since then, the battery keeps going flat. I have no shorts anywhere and I had an issue where the boot release button would turn the interior light on.. I have disconnected that but still have a drain issue. Wiring diagrams are of little insight. … anyone got any tips, time is not on my side as I have limited rest between work and crazy children! 😂
cheers! 
stu 

[Greydog]

Hi Stu

A clamp Ammeter on the live side of the battery will help then start pulling fuses in the boot as it is where the issue started. Shut yourself inside and when the car goes to sleep the ammeter should read just a few milli amps anything higher is the issue. Start pulling fuses in the rear fuse panel if one stops the draw you have the circuit that needs checking. If no joy repeat at the front fuse board 

Question, is the lock the original or is it one that came with the bits you replaced ?

Dave

 

 

 

[X5smw]

Hi Dave. The lock and button are from the donor vehicle. I basically cut and crimped the existing wires to the loom in the upper bootlid. 
the lower bootlid used the existing loom. 
when I had the light issue, it was the rh upper lid courtesy light the that came on when I pressed the lock release button. 
Left one works correctly and all lights extinguish when I lock the car. 

[Greydog]

I would double double check your crimping is there a stray wire strand thats touching something it shouldn't? According to my ex-neighbour (Now a High Up BMW man based the USA) it was late 2003 early 2004 before there were any changes in the X5 apparently the early pre facelift models were fitted with a full loom so any accessories were easy addons. After face lift you needed a loom extension and coding so what you have done really should have been straight forward (but aren't all the "simple little jobs")

Dave

[X5smw]

Thanks mate. I have checked the crimping and it’s all good. 
what might throw it out is the wiring all being different colouring, so I might have a permanent live swapped with a switched live… obviously I wouldn’t be able to tell until the car is sleeping and I don’t know where each live controls . I have a clamp meter en route, I’ll find it! 
 

it can’t be that difficult, there is only about 15 wires in the top boot and no exterior lights. 
surely it’s a lock button, wiper and 2x interior lights. The brake light was not cut along with the aerial module on the spoiler. 

[Greydog]

We soooo love an optomist Stu 🤣

If the wire colours were different that is reall wierd 

Dave

[X5smw]

Well… clamp meter found nothing… I have removed the fuses for the wiper, heater and disconnected the interior lights on the bootlid. I still have a drain somewhere. 
I just removed the plug on the rear wiper and now the car external temp says it’s -35! ….. 

and the bonnet cable has snapped again! 
 

 

[Greydog]

Morning Stu

Going back over note's there were a stack of problems in the early E53's with Magneti Marelli starter motors being the culprit try the clamp meter on the starter cable. Also worth checking the Voltage regulator as they can give issues as well

Also worth checking that the loom in your boot lid hasn't had a dodgy repair

Dave

 She will misbehave until you get rid of the Porker 🤣

 

[X5smw]

…. It’s like 3 teenage women in my house now…. 
problem is… ones in her 40’s… one is 2 and the other is a car! 
 

it’s got to be something with the boot wiring, it’s only happened some I changed that. I think I just need time and peace to work out what’s wrong. 
then open the bonnet though the grilles again! 😂… then who knows!