Morning

 

Strange one here where my 2009 2.0l TDI Superb has, on a number of occasions, lost complete electrical power. Last night was the worst when I had to stop and get some money and when i got back in it completly died. No electric charge at all. There had been no issues starting it when i left the house. Everything from the lights to the central locking were completely dead.

 

A friend came and we used jump leads to the battery and it started straight away. I am going to get a multimeter later and test it this morning but seeing as it went completely dead is it an indication of an ECU issue?

 

The car is obviously 10 years old and has done 146k but it seems very strange to see such a complete loss of electrical power. Has anyone else seen this?

 

 

Updated.

 

Used the multimeter. With ignition off the battery was providing 12.5v and with the engine running it was at 13.95v (ish)

Edited 11 September, 20196 yr by pdrisc

If the main terminals on the battery are tight, check the fuses on the front of the "E" box 

31 minutes ago, nige8021 said:

If the main terminals on the battery are tight, check the fuses on the front of the "E" box 

Thanks Nige

 

Battery terminals are tight but where is the E box?

19 minutes ago, pdrisc said:

Battery terminals are tight but where is the E box?

It's next to the battery 

7 minutes ago, nige8021 said:

It's next to the battery 

 

Just found it. All appears good. No loose terminals and all the fuses seem good. It appears to be one of those annoying niggle faults. 

 

I seem to have eliminated battery and engine fuses. The only change that i have made recently to the car is the addition of a Pure DAB unit which is powered through the 12v port in the centre console. I will have to disconnect that and see if that can be eliminated.

To have a completely dead car, the problem will almost certainly be with either the battery, it's associated cables/ connections, or with the engine bay fuse box.

 

You will need to check these again carefully if & when the fault returns.

 

Don't forget to take the test meter with you whenever you use the car.

Edited 11 September, 20196 yr by PipH

I had a similar issue some years ago in wife's fiesta, it started off occasionally doing it and got worse. It was the big earth lead between the battery and the bodywork that had corroded at the fixing point - as pretty much everything uses the chassis as an earth it gave the impression of a total electrical failure despite battery shoving 13v or something. Check the earth it could be a simple fix. I think it was a braided strap on the Fiesta from memory - but as always - I could be wrong.

Edited 11 September, 20196 yr by VRS_White_Hatch

2 minutes ago, VRS_White_Hatch said:

I had a similar issue some years ago in wife's fiesta, it started off occasionally doing it and got worse. It was the big earth lead between the battery and the bodywork that had corroded at the fixing point - as pretty much everything uses the chassis as an earth it gave the impression of a total electrical failure despite battery shoving 13v or something. Check the earth it could be a simple fix. I think it was a braided strap on the Fiesta from memory - but as always - I could be wrong.

 

That sounds the most plausible thing so far. Putting the jump leads on the battery terminal may have helped make the circuit to get me going again.

 

Will look at that later. 

So an update to this. 

 

I am going to hold my hand up and confess straightaway that I think it all was caused by a "loose" battery connection. So apologies to nige8021 who called it right first time.

 

On 11/09/2019 at 09:55, nige8021 said:

If the main terminals on the battery are tight, check the fuses on the front of the "E" box 

 

When it happened again i actually tried to shake the negative lead and found that it rotated. It wasn't loose but equally wasn't as tight as it should have been. 

 

I have re-tightened the clamps and it seems to have solved the problem. A problem that i caused because i changed the battery a couple of years ago myself!

 

Lessons learnt and all that.