Battery Drain
 

I have a problem that if i can't resolve may lead to the demise of my beloved MG ztt cdti. I cannot find the cause of 2.5 amps of battery drain which is killing a full battery overnight. Having removed the sat nav unit completely ( known previous cause) i am still annoying my neighbours with alarm sounding in early hours.
I know from previous experience that with all doors closed etc the alarm usually shows 3 to 4 amps for approximately 2 minutes and then drops to 50 milliamps. Currently my car has over 4 amps for 2 minutes and then drops to 2.5Amps as the cabin lights extinguish and alarm sets.
2.5A is killing the battery.
As my car has 210k miles on it I am struggling to justify hours / cost of extensive investigation / repair.
Removing fuse 33 ( audio) makes no difference.

Sad but the end may be nigh !:cry:

Don't give up!

Have you put a multimeter on each fuse to see if any are drawing current?

I have absolutely no idea what the problem is but what about pulling a fuse at a time to see when the drain drops and go from there or have you done that?

macafee2

Try this way - https://the75andztclub.co.uk/forum/s...d.php?t=167111


You can begin by pulling the main fuses in the under bonnet main fuse panel, then move to pulling fuses if necessary behind the glove box.

Tried so far .......
 

Removed Sat nav unit.( had no disc anyway !)

checked for current drain across engine bay fuse box except for the pattern of 6 square shaped fuses which I have been unable to extract. None of the Larger fuses appeared to carry the current being drained.

removed fuse 33 ( audio)

Recent faults have been the external air temp sensor which turned out to be harness break. Currently the aircon is not working, worked fine last summer but have recently tried and comressor is not kicking in but haven't had chance to investigate.

Thanks for speedy response folks

Tried so far 2 .......
 

Having been a lifelong Rover fan / employee ( 28 years at Longbridge) and have never owned any car not built at Longbridge or Cowley I have to say even I can't support the logic of locating the cabin fuse box up behind the glovebox!!!! as someone with two knee replacements and rapidly advancing years it is all but impossible !!! Did think if I had a sunroof I could hang by toes upside down !!

Another way of checking for which circuit is responsible for the current drain is to use a multimeter and measure the (small) voltage drop across each of the fuses, and then using the tables here
https://www.powerprobe.com/fuse-voltage-drop-charts
To look up the current drawn.


Something else to check, when the car is locked, does the background lighting on the light switch go out? If not, the light switch could be doing the rest of the car going to sleep properly.
Also, check the glow plugs are not staying enabled (especially if the relay has been wet)

Good luck
Chris

Battery going flat that quick could be the alternator at fault which is draining the battery, use your multimeter to check the alternator output.

Also, have you done any audio mods recently such has upgrading stereo or fitting a dash cam, if so disconnect or pull the fuse and take another reading.

would one of these be of any help


https://www.ebay.co.uk/itm/Automotiv...cAAOSwS~FaXd5V


My aircon wasn't working due to compressor clutch not pulling in. A re-gas fixed it. (for now anyway) Hopefully there is not a leak.



Blackrose

You cannot have it both ways, if you haven't managed to remove the large fuses, you cannot be certain which circuit is any is causing the discharge. There is also a possibility that the starter motor or alternator might be the source of the issue. 2.5amp is a substantial discharge, so should be an obvious and easy source to locate.