Battery Drain on DOME fuse

[Mark Weller]

Hi there, new Toyota owner here with a 2007 Aygo. The Battery is draining fairly quickly maybe a day or two to the point where the central locking doesn't work, nor the car start so a significant drain.

I've done a fair bit of YouTubing and fixed up a number of cars in various ways so not a novice, but electrics is a bit of a new one on me.

There are no modifications to the wiring system, no new dash cams or anything like that fitted. 

I've put a multimeter in line on the negative Battery post and measured the draw which is 60 milli amps. This reduces to practically nothing when I remove the DOME fuse and no other fuses reduce the draw so I am assuming this is the issue and why the Battery drains

From what I can work out - this feeds the interior light, radio and gauges behind the steering wheel.

I've removed the cables to the rear of the radio and the interior light and the drain remains so assumed at this point it was the gauges. So I went there and removed the main power lead into the rear of the binnacle and the battery still drains. Weirdly though the drain in milli amps when measuring drops off when I remove the power lead to the rear of the binnacle (the speedo, odd, warning lights etc). I also tried the same thing removing the fuses from around the binnacle under the cowling, but none of them reduced the drain by any more than 10 milli amps. 

I'm not sure on the acceptable draw on an Aygo, but am at a loss now as to where to go with this. Battery still draining, unless I completely remove the DOME fuse (15A) in which case everything remains OK.

Any ideas greatly appreciated?

Thanks

Mark

[Billyboy81]

Have you got anything plugged in to the OBD port?

[Mark Weller]

6 minutes ago, Billyboy81 said:

Have you got anything plugged in to the OBD port?

No nothing at all

[flash22]

60ma is fine, it can take anything up to 2 hours for everything to shut down,

i would suspect the Battery is done for, It's dropped its capacity - due to the age of the car, it's more than likely had a cheap Battery fitted by a previous owner, get a Bosch/Varta or Yuasa - there is a chance that the alternator isn't charging correctly, or the car is doing short runs

 

make sure it has the correct terminal layout, its all too common for the wrong Battery to be supplied

[Mark Weller]

2 hours ago, flash22 said:

60ma is fine, it can take anything up to 2 hours for everything to shut down,

i would suspect the battery is done for, It's dropped its capacity - due to the age of the car, it's more than likely had a cheap battery fitted by a previous owner, get a Bosch/Varta or Yuasa - there is a chance that the alternator isn't charging correctly, or the car is doing short runs

 

make sure it has the correct terminal layout, its all too common for the wrong battery to be supplied

Thanks - I forgot to add to the post that I've checked out the alternator is charging and under load etc, and all good with that. Battery looks new but I'll get that checked out properly as I don't have the kit for that

It has stayed charged for the past week with the offending fuse removed! though, but obviously more could be wrong with it I guess.

[flash22]

You can check the voltages of the Battery, but it doesn't load test it

60ma isnt a great deal, 2-3 leds can pull that sort of current, the dome fuse supplies a lot of circuits, IIRC it has its own dome cut relay, i will have to pull the diagrams up for that

standard or aftermarket radio ??

[Mark Weller]

1 minute ago, flash22 said:

You can check the voltages of the battery, but it doesn't load test it

60ma isnt a great deal, 2-3 leds can pull that sort of current, the dome fuse supplies a lot of circuits, IIRC it has its own dome cut relay, i will have to pull the diagrams up for that

standard or aftermarket radio ??

It's the standard one I think - I'll get a photo to be sure. . .

[Mark Weller]

4 minutes ago, Mark Weller said:

It's the standard one I think - I'll get a photo to be sure. . .

 

DD7921E0-945E-46EC-AF64-437C3A9C4B9B.heic

[Mark Weller]

9 minutes ago, flash22 said:

You can check the voltages of the battery, but it doesn't load test it

60ma isnt a great deal, 2-3 leds can pull that sort of current, the dome fuse supplies a lot of circuits, IIRC it has its own dome cut relay, i will have to pull the diagrams up for that

standard or aftermarket radio ??

When I checked the draw I disconnected the neg terminal, had the multimeter on unfused 10mamps and then put the neg lead on one lead and the other lead to the Battery post, so that the multimeter was in line. Then started pulling fuses until I got to the dome one. From there I went inside the car to the light, disconnected the door switch, radio and the gauges. Thanks

[simon p]

Get yourself a bosh battery 🤑