Hi all,

Hopefully, someone can help...

Mrs told me the other day that a dash yellow light had come on, possibly the traction control. She drove home but when I looked at it it was fine. This was a few days after she said the dashcam needed looking at because it was coming up with "low voltage."

I tried to read fault codes via OBD2 and it was clear so I drove it around for 20 mins and it was OK.

She rang me earlier to say that she had turned the ignition off/taken the key out and the engine was still running. She stalled it and rang for Green Flag to come to take a look.

In the mean time, she said that the dashboard lights etc is all on and the door light went on/off with the door opening/closing.

They thought it might be the ignition switch, which matched a bit of research I did on here where someone said, "Common problem with that switch since it came out in the 95 A4, test the concept by unplugging it. Part number 4B0 905 849"

Anyway, the car was taken to a mate's garage and now it won't start and the central locking doesn't work.

Does this sound like the battery? It had a Varta one on about 5 years ago so it is probably due to fail. I've not seen any "low voltage" warnings on the car (I seem to remember seeing this when the first battery went) but the Swing radio is stuck on AUX most of the time and I think the warning was on it.

Or, perhaps the ignition switch is faulty AND the battery is knackered.

Any ideas, please?

Thanks in advance.

I would say the ignition switch has gone if it continued to run once key removed. I am surprised the imobilser didn't come on ? If the switch is stuck in pre ignition mode then that could flatten battery if left for a while. I would presonally disconnect battery and put on charge or jump it and see if the switch works plus central locking etc. I would also keep the battery disconected until you discover why it continued to run. Last thing you want is for the car to start itself.

Alasdair

17 hours ago, Alasdair1 said:

I would say the ignition switch has gone if it continued to run once key removed. I am surprised the imobilser didn't come on ? If the switch is stuck in pre ignition mode then that could flatten battery if left for a while. I would presonally disconnect battery and put on charge or jump it and see if the switch works plus central locking etc. I would also keep the battery disconected until you discover why it continued to run. Last thing you want is for the car to start itself.

Alasdair

Hi,

Thanks for your response.

When the car was taken to the garage, they said it was doing lots of weird things like the wipers running by themselves etc. I persuaded them to put a battery on it and, afterwards, it did start and drive and they managed to get the central locking operational from the keyfob although it wasn't 100% reliable.

I did mention the door interconnect harness and they gave that a wiggle and said the drivers door seemed to lock better but that might just be incidental.

They're putting a new battery on it today so, hopefully, it will be as simple as that.

Thanks again,

D

Glad there getting to the bottom of it hopefully. I would perhaps replace ignition switch anyway as you said it continued to run when key was removed. Does sound like something is stuck/worn in there. If the voltage of the battery is too low it can cause random problems with electrics/electronics but the switch is either on or off and shouldn't be affected by low voltage.

Alasdair

4 hours ago, Alasdair1 said:

Glad there getting to the bottom of it hopefully. I would perhaps replace ignition switch anyway as you said it continued to run when key was removed. Does sound like something is stuck/worn in there. If the voltage of the battery is too low it can cause random problems with electrics/electronics but the switch is either on or off and shouldn't be affected by low voltage.

Alasdair

Agreed. I suspect that the battery may have got flattened by the ignition being stuck on. Will see later when they have changed the battery.