Electrical gremlins = Faulty ignition switch?

[injidup]

I've just picked up my 06 GTI from the dealers after having the ignition switch replaced under warranty.
The problem was that occasionally, usually under heavy drain on the electrical system - night time, aircon and lights on, then flash the headlamps, put into reverse, etc, I'd get a beep from the dash and then various warning lights would come on (abs, steering, etc) and the radio would cut out. Occasionally the power steering would stop working and the steering would become heavy. Luckily this usually happened when parking, not on the road! Also, I could detect a slight dimming of the headlights whenever I put the indicators on.
The battery seems fine as the car starts easily.

I took it to the dealers as I had a warranty. They said it needed a new ignition switch, and that has been replaced.
Last night when I drove the car, the radio cut out again (but no beeps of warning lights!).

Has this happened to anyone else, and is it a known issue?

I'll check the radio connections (Aftermarket, but all connections soldered).

Hopefully it is fixed, but it seems an odd repair for the symptoms.

Cheers,
Kev.

[seangti]

Have you had the alternator checked to ensure it's cranking full power? And your battery tested, a 1v drop in battery performance (so 10-11v) will still usually start the car, but between a low voltage and low alternator performance it may not be handling the high load circumstances.

Could try driving for a week or two with the stereo turned off to see if it's something that's causing/contributing to your grief. Are you running an amplifier??

[Guy_H]

I have seen several of the electronic power steering heads fail - they start to take out the main circuit electrics - including ABS controller etc - you will see low voltage codes thrown in different modules & have intermittent communication with the power steering.

[philthy]

My earth strap (black wire from negative terminal on the battery to the chassis) was damaged, which gave me the symptoms described. With the car off check that the voltage across the battery terminals is the same as the voltage from the positive terminal to ground.

[blackbetty]

*2 on the battery earth cause for these symptoms. i checked my voltage and it was a bit lower from pos term to end of earth cable.
so i replaced the earth cable and all symptoms were gone. been fault free now for months

[injidup]

I checked the voltage and it's 13.4 across the terminals (engine off) and 13.4v to the earth strap and several earth points around the engine bay.

What's annoying is that the VW dealers have checked this and replaced the ignition switch and it still happens! I'll be going back to them!

Thanks gents!

[injidup]

Well I went back to VW and they ran some more tests and this time they say it's the earth strap.
They are going to replace it, but it's not covered by the warranty.

I'll report back once it's been replaced.

Thanks gents!

[philthy]

My issue was intermittent and I swear I checked the strap several times before I figured out what was going on.. When I actually found the low voltage I gave the strap a good wiggle and the voltage drop went away.. Must have had some internal corrosion or something. Anyway, have had no dramas at all since new strap, so hope it works out for you.

[injidup]

Earth strap has been replaced and ...so far... no more gremlins!
And covered by the warranty!

[waxgti]

hey guys anyone have the part number for the strap, i have a feeling this may be the problem. my gti is not starting, but when left overnight, the battery recharges, and when i pump my pedal it has started on occasion, taking it to a battery place to check the voltage but think i should replace the strap as when i touched it, it was stiff and i feel it may be rusted or something inside??

thanks

[zib123]

I've had exactly the issues mentioned with my VW Polo 9N (2001-09): intermittent abs warning lights appearing; power steering failure; car failing to start randomly; radio cutting out; power to the headlamps cutting out...etc.

Took it to an auto electrician - no issues recorded.

On a separate occasion it was with a regular mechanic who was fixing another problem when it was having the starting issue mentioned above (turn the ignition - dash lights appear as normal - turn to start it but nothing happens... no starter motor, nothing!) he recognised the power was cutting out and noticed the earth cable was red hot when he touched it. Wiggling the cable seem to resolve the problem on this occasion and the car started without issue. So I cleaned up the connectors and it was fine for a few days. Then it started happening again and wiggling the cable wasn't working anymore. So I decided to order another cable from VW.

So I've replaced it and it's been fine now - it's been about 4000 miles since the change and none of the issues listed above have recurred.

I'd say there's a design flaw or something with the cable: the image below shows how the new one has changed from the old - i.e they've added extra insulation/sleeves...

The part number is: 6Q0-971-235-J and the description is Harness. If anyone's experiencing the issues described this is definitely worth trying first - it's only around £30.