Focus Mk2.5 Excess Parasitic Current Draw

[AiBrs]

Hi folks,

Having some problems with my 58 plate Focus. The car isn't seeing much use at the moment as I have a new job that isn't commutable by car. At one point it was idle for almost 3 weeks and the battery drained completely (less than 4V). This is a new battery, only 4 months old.

Finally got around to measuring the current drain today, made up some leads for my multimeter with large croc clips on the end.

With doors closed and car locked the current draw was around 520mA (instrument cluster still switched on).

After a while the instrument cluster switched off and this dropped to 195mA. Still pretty high.

I tried pulling the following fuses:

• Radio - removed it completely and removed fuse - no real difference (android unit)
• Cigarette lighter - no real difference (I do have a 12V - 5V adaptor wired here so I suspected this)
• Instrument cluster - pulled the fuse for this because it comes on every time the car is unlocked and was making measurment difficult. Current dropped to 163mA after this. So looks like the instrument cluster or some related canbus module draws around 30mA when off.

Does anyone know what else could be drawing this much current? 160mA seems pretty high to me and this is the reading I was getting after pulling the fuses for the instrument cluster, radio and cigarette lighter and having the car locked.

Cheers

[dezwez]

light in the boot not saying on when you lock the car just a thought

[AiBrs]

light in the boot not saying on when you lock the car just a thought

Thanks for the suggestion. Just had a look and the boot light goes off okay when the boot is shut. All the other lights are off too, footwell, roof etc.

[synaesthesia]

You say you have an android unit - when you pulled it out, did you also pull out the canbus module?

[AiBrs]

You say you have an android unit - when you pulled it out, did you also pull out the canbus module?

I didn't actually. I just pulled the connector block out of the back of the radio. Is that canbus module known to cause issues?

[synaesthesia]

Not in particular, but the chinese units suffer from variable build quality depending on how much the 12 year old slave building it was concentrating. Despite the amount of time I've spent fiddling with these things I can't remember for the life of me if the canbus module went into the back of the head unit only or if it had any connection to the car if the radio wasn't present - hence I could be talking rubbish! :)

[AiBrs]

I just had another pop at this. Can't touch it during the week given that it's dark at 5 now and I'm just out on a public road.

This time I completely removed the radio and it's harness including the canbus module but it didn't make any difference. Also removed footwell bulbs, boot bulbs and removed the interior light fitting from the front.

Then I setup the multimeter so I could see it from inside the cabin and I pulled *every single fuse* one by one. As before it was 150mA with the fuses for the instrument cluster, cigarette lighter and radio removed.

The only one that made any difference was fuse 104 with is marked as "battery saver, interior lamps". This caused a drop of 50mA so I left this one out and continued (still at 100mA). None of the other fuses made any difference.

Then I moved to the engine bay fusebox and again removed *every* fuse and *every* relay one by one and nada. Still 100mA on the meter.

I'm kind of at a loss now. This wouldn't even be a problem if the car was used daily but as it is it's just getting used at the weekend (the battery was back down to 11.7V this morning)

Anyone on here an auto electrician with any bright ideas? Or does anyone know someone that could help with this? I'm in Bristol.

[JW1982]

On the Focus MK2/MK2.5 the CANbus system goes into sleep mode approximately 30 minutes (generally between 15 and 45 minutes depending on some of the car's options) after the car is locked. This can be recognised by the instrument cluster display. The instrument cluster display is only switched on (illuminated) if the CANbus system is active.

You can only measure the parasitic current if the CANbus system is in sleep mode. Measuring when the CANbus system is still active makes no sense. When the CANbus system is active all available CANbus modules will still be active and consuming power.

[AiBrs]

On the Focus MK2/MK2.5 the CANbus system goes into sleep mode approximately 30 minutes (generally between 15 and 45 minutes depending on some of the car's options) after the car is locked. This can be recognised by the instrument cluster display. The instrument cluster display is only switched on (illuminated) if the CANbus system is active.

You can only measure the parasitic current if the CANbus system is in sleep mode. Measuring when the CANbus system is still active makes no sense. When the CANbus system is active all available CANbus modules will still be active and consuming power.

Agreed but I thought I may have been replicating a CANbus shutdown by removing power to the instrument cluster. Last weekend I waited for the ~25 mins for the instrument cluster to shut down after the doors were locked and noted the current to be 195mA. At that point I unlocked the car again and removed the instrument cluster fuse which led to a reading of 165mA without waiting. Today I just started by removing the instrument cluster fuse and got back to that reading again.

[Dee_82]

I had the same problem, turned out it was the bluetooth module above the glove box, pulled the plug out if it and all was well.

failing that you will need to start yanking fuses but be sure to leave it about 20min, many of the cars modules take time to shut down properly

this is especially relevant to you because of the android HU, I have a feeling the BT module is controlled by the HU and since you have an aftermarket one it doesn't know its to turn off.

at least that is exactly what happened with mind, plug my BT module in and my current draw goes up and stays up, pull it or put the original HU in and it goes down.