Battery drains

[Stephen Rigby]

Ive a 270d 53 plate.
I have a battery drain fault. The drain is pulling 4.7amps when everything is off.
Consequently every morning for 2 days the battery is flat.
The alternator is charging well.
Ive removed the boot interior lamps.
Ive got a clamp on ammeter on the battery you can see it drain ??
Any one hard a similar fault.

Regaurd steve.

 

[Blobcat]

Could be faulty regulator pack in the alternator
You can measure for a drain by measuring the voltage drop across the fuses. That way you can check without removing the fuse

 

[Richard Moakes]

I have one of these https://www.amazon.co.uk/Cal-Van-Tools-74-Amp-Hound/dp/B00M7S28MQ it will measure the drop across a fuse in circuit and display the current flowing

 

[mattkh]

Ive got a clamp on ammeter

Great.
So, with the engine not running, if you put it on the thick cable going from the alternator to the battery, how much current does it show..?

 

[Flyinspanner]

Have you had the battery stress tested? It could be an internal short.

If alternator is ok, (maybe get the output tested to fully test the bridge rectifier) then use your clamp meter set to mA range, over battery cable, and take out a fuse at a time to find which system has the drain.
videos on YouTube about it.

if you have Comand allow 15mins after shutting down car for it to go to sleep.

If you have a block heater on yours, check that, as they can fail, and have a big drain, yours is somewhere around 60w so whatever it is will also generate some heat, feel if any components stay warm?

 

[Stephen Rigby]

At the battery in the boot .
When the car is locked.
And setteld down .
I get 4.7amp with my ammeter on the battery cable.
The charge alternator is charging and it was fitted 2 mths ago its a genuine Bosch. Its charging as it should.
I am very electrical minded.
But any help would be appreciated.
I will have to eliminate each circuit.
4.7 amps is a lot of power ??
I was checking to see if any one has had a similar problem.
Thank you for the help.

 

[Stephen Rigby]

Have you had the battery stress tested? It could be an internal short.

If alternator is ok, (maybe get the output tested to fully test the bridge rectifier) then use your clamp meter set to mA range, over battery cable, and take out a fuse at a time to find which system has the drain.
videos on YouTube about it.

if you have Comand allow 15mins after shutting down car for it to go to sleep.

If you have a block heater on yours, check that, as they can fail, and have a big drain, yours is somewhere around 60w so whatever it is will also generate some heat, feel if any components stay warm?

Are you thinking glow plugs are staying on ??

 

[Stephen Rigby]

Have you had the battery stress tested? It could be an internal short.

If alternator is ok, (maybe get the output tested to fully test the bridge rectifier) then use your clamp meter set to mA range, over battery cable, and take out a fuse at a time to find which system has the drain.
videos on YouTube about it.

if you have Comand allow 15mins after shutting down car for it to go to sleep.

If you have a block heater on yours, check that, as they can fail, and have a big drain, yours is somewhere around 60w so whatever it is will also generate some heat, feel if any components stay warm?

Ive put a new battery on 1st time . Thinking it was the battery. But the next day with a new battery it was dead. Completely

 

[Stephen Rigby]

Great.
So, with the engine not running, if you put it on the thick cable going from the alternator to the battery, how much current does it show..?

4.7 amp

 

[Stephen Rigby]

Could be faulty regulator pack in the alternator
You can measure for a drain by measuring the voltage drop across the fuses. That way you can check without removing the fuse

Its a new bosch alternator 2mths old.
Its charging well at14.v and with a flat battery 50amp.
The amps lower as it's changing?
To drop test each fuse are you thinking + to each fuse with a meter ? I have a good fluke meter.
Thanks steve

 

[Tony Dyson]

If you decide to start looking in your fuse boxes for the leak, a leak of 4.7A would create a PD of around 10mV across the fuse link you should be probing for but just take a step back to your post 13

4.7 amp

Engine NOT running, this should be zero! This is indicating your fault is clearly your Alternator or the diode pack attached to it, when you replaced the alternator did you replace the diode pack as well?!

 

[mattkh]

4.7 amp

Thank you for doing the test.
Sooo with the engine not running, 4.7 Amps are going through the thick alternator cable towards the alternator, right.
How warm does the thick cable get..?

 

[Blobcat]

Its a new bosch alternator 2mths old.
Its charging well at14.v and with a flat battery 50amp.
The amps lower as it's changing?
To drop test each fuse are you thinking + to each fuse with a meter ? I have a good fluke meter.
Thanks steve

You measure across the fuse as per Tony above. The blade fuses have 2 little connections on the back you can measure the voltage across.

Although as per above of it’s going back to the alternator then it’s like to be the diode pack.

 

[RhodieBill]

Sorry, not too sure if this will be any help but the only drain I've seen on mine is a little clear tube plugged into one end of the battery.....????

 

[Stephen Rigby]

Thank you for doing the test.
Sooo with the engine not running, 4.7 Amps are going through the thick alternator cable towards the alternator, right.
How warm does the thick cable get..?

I have only tested at the battery end in the boot.
I will test at the alternator end later.
I

 

[Stephen Rigby]

If you decide to start looking in your fuse boxes for the leak, a leak of 4.7A would create a PD of around 10mV across the fuse link you should be probing for but just take a step back to your post 13

Engine NOT running, this should be zero! This is indicating your fault is clearly your Alternator or the diode pack attached to it, when you replaced the alternator did you replace the diode pack as well?!

What do you mean post 13.?

 

[Stephen Rigby]

Still looking for the fault.
Today i removed each fuse and relay from the fuse box under the bonnet (drivers side).
And everyone at the internal fuse box on the end of the dash (driver's side ).
Still no big change still shows 4. To 4 .7 amps at the clamp on ammeter in the boot .
I will try to get to the charge alternator cables tommorow. Its difficult to get to .

 

[Stephen Rigby]

Is there a fuse box on the passenger side foot well area ??? I can't see one.

 

[mattkh]

I will try to get to the charge alternator cables tomorrow. Its difficult to get to .

In that case, here is an alternative.
The thick cable from the alternator goes to the battery positive terminal. So follow the thick cable from the alternator towards the battery and use the clamp on a convenient to get to point.

 

[Stephen Rigby]

In that case, here is an alternative.
The thick cable from the alternator goes to the battery positive terminal. So follow the thick cable from the alternator towards the battery and use the clamp on a convenient to get to point.

I think its showing as going to f52 under the floor i will look asap.
The poss on the battery goes to another surge unit with several large cables.
Thanks