Hi, 

I bought a Octavia from 2004, 1.6 engine. 

Suddently One Day, the engine did not want to start. So the battery Was drained. We replaced it with a New One and still the same. The alternator is charging correctly. 

We found out, that it has a current drain of about 900mAmp. We located that the central locking system Was the One Who Was draining it. We removed the central locking unit behind the passenger side glove compartment, and then it went dont to 400mAmp.

But with All Doors closed and the car totally switched off, the amps Was going from 400 to 250mAmp, up and down, like it Was a relay to some alarm going off. Nothing is flashing or beeping. 

After we remove the central locking unit, we tried removing fuse 16 in the engine Bay, and the amps went All the way down to under 70 m Amps. 

So can anyone help me further with this? 

70mA is a tiny current draw and probably just the ECU/radio clock standby draw.

 

Something fed by F16 is faulty?

Yeah, but we only get 70 mA after we disconnect the central locking unit and F16 wich is the fuse to the main control unit to Every component in the car.

The problem we Are having i think is some sort of an alarm is going of, like a relay activating for some time bringing the amps up to 400 mA, and then after excatly 3-4 seconds it goes down to 250mA, and the it goes on and on. 

Rather than probing wires try pulling all the internal fuses and replacing them one by one to locate the source of the drain.

So i have already tried pulling One fuse at a time to locate the drain. And the drain comes from fuses going to the central locking system, and F16 in the engine compartment. When everything is connected, and the car is shut down, you can hear a relay clicking, resulting very high mA and after seconds going down to around 800mA.

 

Any DTCs?

 

Does the alarm siren work?

 

The age of the vehicle suggests the alarm battery has long since died and in doing so has leaked electrolyte over the PCB causing parasitic current draw.

The car does not have any siren sound, there fore i dont know if it has One that is faulty or not. 

I Will recheck All fault codes again, and see what the car says. 

Alarm battery, where? Does Every Octavia has this alarm system with battery and siren? 

 

My problem is very similar to this:

https://www.briskoda.net/forums/topic/404972-battery-drains-20-tdi-16v/

A non functioning alarm sounder is usually the first sign its battery has expired.

 

I don't know if all Octavia models have an alarm siren, the unit is located behind the right front inner wheel arch.

9 hours ago, MicMac said:

70mA is a tiny current draw and probably just the ECU/radio clock standby draw.

 

Something fed by F16 is faulty?

 

You are out by a factor of 10 MicMac, 7ma would be a tiny quiescent current draw, 70ma if maintained would result in a discharged battery if the vehicle is not regularly used.

 

Most of them drop down to 10-15ma after the Canbus has gone to sleep.

 

However, 7 or 70ma is tiny compared to what is going on with the OP's vehicle.

 

That they dont have battery problems does point to the alarm siren being activated as it should time out after a few minutes without draining the battery too much, I would have expected to see the hazard lights flashing though.

 

The OP may want to consider timing how long the 400ma discharge is maintained and also whether they have their multimeter on the correct range and are reading the digits correctly, is it 400ma or 40ma?

Hi again. 

So after long time, i checked the draining again, making sure the car Was in sleep mode, and checking correctly at My multimeter set at 10A.

I had a 700mA draw in sleep mode. Going down to 400mA Every 2 seconds and up again. 

I took out the fuse for the radio, and it went down to 0mA.

So now i know it Was the radio. I have the original Blues radio. 

Let the car sit for 3 days without fuse for radio and the car starts as normal. So No draw. 

How do I fix the radio issue here now?