I've recently bought a 2014 Ford Focus 1.6 TDCI Titanium estate from a independent dealer.

Since I've owned it the battery keeps going flat. I've noticed that after 10 minutes of the car being locked the headunit will turn on and play music through whatever it was playing through - cd player, radio, Bluetooth, or USB. This seems to run until the car goes flat or I next drive it, i.e. morning or lunchtime.

When I was buying it I noticed that a few buttons from the headunit weren't working so they replaced the headunit prior to purchasing it. I noticed that the APIM unit had a different VIN number and I believe the satnav module was changed as I now have 2 Nav SD cards.  Since then I have changed the Bluetooth module so that I could upgrade it to Sync 1.1 from 1.1. I was hoping that changing the module would fix it but it still turns on...

I've run-out of ideas on how to fix it so would greatly appreciate some advice. 

 

So it's been turning back on several times through the night. Each time I open the car up, turn it off and then lock the car. But it turns on again after 10 minutes.

I've used a clamp meter to check the current once the head unit has come back on and attached image.

I've just used used Forscan to program the APIM back to its original as-built parameters, thinking that might fix it, but it has just turned back on again after waiting inside the car for 10 minutes. 

Is it normal for you to have to turn on the head unit when you normally start it? As it's never turned on itself automatically with the engine start button. I thought that perhaps the wiring has been messed with but it looks unabused.

I've pulled out fuse 67 and waited until full shutdown to check on the current through the clampmeter again. With the headunit completely off, it's all the way down from 2.34 amps to 0.179 amps.

I guess that confirms it is the headunit that is draining the battery, but leaving out the fuse isn't a long term fix so I now need to work out why the headunit is turning back on after the full shutdown.

The saga still continues. I had the dealer have a look at it and he's changed the CD player unit, but the head unit still switches on around 30 seconds after the car has gone in full shutdown mode ( circa 10 minutes).

The only thing I haven't changed is the display/SatNav unit and the fascia with the buttons. 

I did reset the battery monitoring to get my stop/start working the night before this all started. I wonder if that's related, and I should check the stop/start relay module?

The only other thing I have to mind is the ignition barrel could need checking?

Anyone got any ideas?

This issue has now been resolved, I purchased a set of SatNav/display unit and button fascia from gumtree. Once fitted the head unit stopped turning on over night. I hope somebody finds this useful.

Glad to see you found a resolution, might be helpful for other people in the future.

Guessing you got no replies as nobody had come across it before!