2015 1.1 P0420 and Not charging battery.

Can anyone help. C3 2015 1.1

The car would not start on 1st March. So had a new battery installed. And was working fine until 14 April when the engine warning light came on. With code p0420. I did not use the car again until 23rd April. When again the car would not start. Took it to a local garage who installed 2 new altinaters but neither would charge the battery. Then reinstalled the original altinater but did not connect one of the wires. And it charges the battery and works. So sounds like an electrical fault. The garage has said they don’t know that’s wrong and can’t fit it.

Chris90 wrote: ↑Fri Apr 26, 2019 4:08 pm Can anyone help. C3 2015 1.1

The car would not start on 1st March. So had a new battery installed. And was working fine until 14 April when the engine warning light came on. With code p0420. I did not use the car again until 23rd April. When again the car would not start. Took it to a local garage who installed 2 new altinaters but neither would charge the battery. Then reinstalled the original altinater but did not connect one of the wires. And it charges the battery and works. So sounds like an electrical fault. The garage has said they don’t know that’s wrong and can’t fit it.

Hi Chris90

If bypassing the smart charging (I assume this is what they did by not connecting one of the wires) keeps the car running and having a mechanic actually look at the engine to say they can't fix it, I would say, leave it as it is.

It will cost time and money to get it working, diagnosing the charging and then replacing the loom or the BSI or the engine ECU, not worth it.

Your P0420 is a bit more important, probably an O2 sensor, but any part of the ignition and injection system or cat could be at fault.

If the charging is OK for now, the priority will be P0420 as this could be a bit more of a problem to identify.