VW Polo start up / light problem

[laura1625]

I have a VW Polo 2012 and have been having a strange issue with my lights/start up.

My back light had been letting water in and had completely rusted my circuit board so I replaced the full back light. Since I have replaced it, my tail light doesn't work properly. So when I get in my car and start the engine a warning light sometimes appears showing that the light isn't working. I get out and give the light a tap and it comes back on. This is where the problem is...I then restart my car to clear the warning light and the engine wont start properly. I have to turn the key and rev the engine for it to start then keep my foot on the accelerator for a minute before i can release it. If i release it too fast the car just dies. It only does this when i tap the light for it to work and not if the light is just working when i get in the car.

Anyone know why this might be or how i can resolve this?

Thanks.

Edited by laura1625 on Wednesday 3rd April 15:12

[Penelope Stopit]

What is a back main light?

[laura1625]

Tail light

[Penelope Stopit]

There could be a bad earth at the rear of the vehicle that is causing the rear lights and fuel pump to fail

Only a guess

[laura1625]

It is only the tail light that is a problem. Indicator and reverse light are both still working as normal.

If it is the earth wire, do you know how this can be fixed? (Does it need to go to the garage or can it be done at home?)

[Penelope Stopit]

I doubt it's an earth problem as the other lights are working

[GreenV8S]

The problems after the 'tap' might be consequence of stopping and restarting in that situation rather than that the tapping itself has caused a problem.

If I were you I'd unmount the light assembly and try to reproduce the light failure by wriggling wires and connectors. It may just be a connector not fully home, or not tight enough, or some surface corrosion.

[laura1625]

GreenV8S said:

The problems after the 'tap' might be consequence of stopping and restarting in that situation rather than that the tapping itself has caused a problem.

If I were you I'd unmount the light assembly and try to reproduce the light failure by wriggling wires and connectors. It may just be a connector not fully home, or not tight enough, or some surface corrosion.

I think there's defiantly a link with the light and the car not starting. My car starts fine all other times except when i've fixed the light. If i turn my car on and the light is working it doesn't have any problems and if i just stop and restart my car without messing with the light it also works fine.

I do think there is defiantly a problem with the light itself and so I will have a look at the connection and try fix that. Hopefully once that's fixed then I won't need to do the tapping/restarting again which will solve my problem.

I just wondered what the link could be. Like whether my battery had a fault and thats why it is struggling to do both the light and restart at the same time or whether it was a bigger issue.

[GreenV8S]

laura1625 said:

I just wondered what the link could be. Like whether my battery had a fault and thats why it is struggling to do both the light and restart at the same time or whether it was a bigger issue.

I had a battery with a broken post that would do some pretty wierd things, but nothing like you're describing.

You say you only see the running problems when you start the engine, tap the light and then restart the engine. How often would you start the engine in quick succession if you didn't see the lighting problem? My suggestion is that it's what you're doing because of the light problem that causes the running problems and they are not linked directly. Engines that have just been cold started are in a pretty unusual state and it wouldn't be completely unusual for repeated cold starts to cause running problems.