[Ren 25]

Hi, I had been enjoying my 2009 1.4TSI Eos with only 54.000 miles on the clock. Although it is not great using during very cold winters as the windows freeze up. I really don't like having to Mot a car during the winter as I need to work on it outside in the cold.
After taking my car for the mot last week it passed with just 2 small advisories, however on the way back the electrics all went crazy. No indicators, wiper, horn, boot release, dashboard lights etc etc. The car was still driving well with no engine warning light on dash. The battery completely drain overnight so I carried out a few tests with the multi meter, pulling fuses to look at the readings. The amps leakage was still high although 1 x 5 amp fuse relating to the fuel pump did show a reduction when pulled out. I then disconnected the battery and put a wire across the leads for 5 mins. I now have some electrics back working with the ignition on but if I start the engine they all start to fail again.
I phoned a mobile auto electrician but he told me that he would have little success in finding the fault & would charge £60 an hour.

Has anyone experienced these problems & give any advice?

Cheers

Keith

 

[voxmagna]

Have you been charging a flat battery on the car or jump started it? If an auto electrician says they would have little success finding the fault, then you can expect it will be something a DIYer won't find easily either? There are far too many unknowns and scenario possibilities to attempt to give help and it's best left to somebody who can actually work on your car? I would always start with a diagnostics scan because that should tell you what modules are missing power or if a power source driver is faulty. These kind of faults can boil down to something simple like a bad battery ground, but have a tendency to escalate to other things and getting stuck in can make matters worse. If you start the car and faults come back I would be concerned something might be wrong with the battery or voltage regulators. If the car is running on the alternator, voltage spikes and a bad power source can make things worse.

Yes frozen windows (and locks) are a pain on the EOS because the top seals are always wet and ice over. When my EOS is driveway parked in Winter I leave a small heater in the footwell. I made mine from some 60W lamps, a biscuit tin and an electronic thermostat. But you can buy similar from garden centers. Make sure it has a frost thermostat. You set this to about 5 degC which stops the icing up and doesn't take much juice. Alternatively buy a car cover.

 

[paul_c]

I phoned a mobile auto electrician but he told me that he would have little success in finding the fault & would charge £60 an hour.

Has anyone experienced these problems & give any advice?

Cheers

Keith

£60 to go "huh?" and shrug their shoulders seems good value. Normally they charge about £95/hr for that. It can't be too far off main dealers (you get a posh "huh" and coffee; or just a posh "huh" and made to wait outside, in Covid19 era) prices.

 

[aku-aku]

Get yourself proper diagnostics (VCDS or OBDeleven). Note all the faults that are currently logged, then clear them. With the ignition on but engine off, check for faults and make sure none are listed. Start the engine, wait for it to all go haywire, then stop the engine, put the ignition back on, and check for faults again. This will give you an indication of the issues (but not necessarily the cause).

Given the problem only presents itself with the engine on, my wild stab of a guess would be that something is up with the alternator or voltage regulator - or the wiring to them. A diagnostic log, obtained according to the instructions above, could quite easily prove that hunch wrong!

 

[Ren 25]

Get yourself proper diagnostics (VCDS or OBDeleven). Note all the faults that are currently logged, then clear them. With the ignition on but engine off, check for faults and make sure none are listed. Start the engine, wait for it to all go haywire, then stop the engine, put the ignition back on, and check for faults again. This will give you an indication of the issues (but not necessarily the cause).

Given the problem only presents itself with the engine on, my wild stab of a guess would be that something is up with the alternator or voltage regulator - or the wiring to them. A diagnostic log, obtained according to the instructions above, could quite easily prove that hunch wrong!

Get yourself proper diagnostics (VCDS or OBDeleven). Note all the faults that are currently logged, then clear them. With the ignition on but engine off, check for faults and make sure none are listed. Start the engine, wait for it to all go haywire, then stop the engine, put the ignition back on, and check for faults again. This will give you an indication of the issues (but not necessarily the cause).

Given the problem only presents itself with the engine on, my wild stab of a guess would be that something is up with the alternator or voltage regulator - or the wiring to them. A diagnostic log, obtained according to the instructions above, could quite easily prove that hunch wrong!

Thanks for all the advice.
My basic scanner only reads engine related codes. Can you recommend a more advanced scanner?
With the engine running, the battery reads 14.2 volts which seems a reasonable charge from the alternator.
I had to change a faulty fuel pressure regulator recently but apart from that I have had no real problems with the car up until now, although it has not had much use during lockdown.

 

[voxmagna]

With the engine running, the battery reads 14.2 volts

But what is the battery voltage during cranking? Covid layup, flat batteries and cold weather can contribute to a failing battery. If the cranking is slow and the battery voltage can drop below 9 volts it's time for a new battery. If your battery is suddenly going flat overnight when it was o.k before, you should suspect the battery and check it first before looking for anything else.

 

[Ren 25]

But what is the battery voltage during cranking? Covid layup, flat batteries and cold weather can contribute to a failing battery. If the cranking is slow and the battery voltage can drop below 9 volts it's time for a new battery. If your battery is suddenly going flat overnight when it was o.k before, you should suspect the battery and check it first before looking for anything else.

But what is the battery voltage during cranking? Covid layup, flat batteries and cold weather can contribute to a failing battery. If the cranking is slow and the battery voltage can drop below 9 volts it's time for a new battery. If your battery is suddenly going flat overnight when it was o.k before, you should suspect the battery and check it first before looking for anything else.

But what is the battery voltage during cranking? Covid layup, flat batteries and cold weather can contribute to a failing battery. If the cranking is slow and the battery voltage can drop below 9 volts it's time for a new battery. If your battery is suddenly going flat overnight when it was o.k before, you should suspect the battery and check it first before looking for anything else.

Hi, battery was fully charged when fitted & already tried 2 other batteries.
Strange that some of the electrics are working now with the ignition on but not when the engine is running.

 

[paul_c]

Thanks for all the advice.
My basic scanner only reads engine related codes. Can you recommend a more advanced scanner?

VCDS and OBDEleven are "more advanced scanners".

Even once the codes are read, you may be none-the-wiser. Post the results of the scan here and/or Google them for more direction. It might be that there's 1 or 2 codes which more or less relate to the problem, and a bunch of other red herring codes which are downstream of the original failure or other unrelated things.

 

[voxmagna]

As paul-c says, diagnostics should tell you something, but your kind of fault might throw up several codes which doesn't mean there are several faults.

Strange that some of the electrics are working now with the ignition on but not when the engine is running.

There could be several reasons. When you crank an engine there's a huge load on the battery via the starter motor, relay and cables. If there's an issue with poor wiring connections particularly ground terminals, important circuits can get 'jolted' and stop working. When you first turn on the key the electronic modules are self checked and at this time you watch the dash lights very carefully or shoot a short video to play back. ALL the dash lamps should light momentarily then go out leaving only a couple lit - charge light, seat belt etc. If other lamps are lit, then self checking those modules at key on has failed and that's what diagnostics will tell you. If you then start the car and other dash lamps that were out come on, then starting the car caused fault conditions. Key on before cranking is a good point to do the first scan for fault codes. If that checks out ok, your problem could be caused by starting, not that the engine is running.

I'm not suggesting you go and look at things you might not know about, but some members have had issues with the main fusebox in the engine bay. This is the 'big boy' where all the vehicle high current is fused and routed. One member found theirs melted, most likely due to dirty connections on a high power fuse holder which had gone unnoticed. ABS plastic is a good low voltage insulator, but melts easily if it is allowed to get hot. Once it burns and chars, it's no longer an insulator. There's also a couple of BIG and very important chassis grounds sitting under the fusebox (or was it the battery box?) that can get corroded. One of them is for all the fat brown ground return wires in the loom.

This type of faults is worrying because if the main starting and ground cables have bad connections, the starter could pull current through the loom ground wiring. This hypothetical fault scenario could be as you describe and its the whole car ground wiring getting a raised voltage potential during starting and after the system modules have been self checked that could cause some regulator modules to shut down. The car can still start but the starter is taking its current from the wrong wires. Diagnostics won't tell you this, it will just put up a bunch of faults. V.W try to keep the main loom grounds separate from the battery starter ground to prevent this happening. But some do aftermarket mods attaching wires to the battery terminals and screwing down this and that to the bodywork. Once this is done, it destroys the loom protection designed in by V.W. That's why a decent auto electrician may charge £90 because if this is the problem and you keep starting and running the car, it may impact on control modules and the wiring loom.

 

[Ren 25]

As paul-c says, diagnostics should tell you something, but your kind of fault might throw up several codes which doesn't mean there are several faults.
There could be several reasons. When you crank an engine there's a huge load on the battery via the starter motor, relay and cables. If there's an issue with poor wiring connections particularly ground terminals, important circuits can get 'jolted' and stop working. When you first turn on the key the electronic modules are self checked and at this time you watch the dash lights very carefully or shoot a short video to play back. ALL the dash lamps should light momentarily then go out leaving only a couple lit - charge light, seat belt etc. If other lamps are lit, then self checking those modules at key on has failed and that's what diagnostics will tell you. If you then start the car and other dash lamps that were out come on, then starting the car caused fault conditions. Key on before cranking is a good point to do the first scan for fault codes. If that checks out ok, your problem could be caused by starting, not that the engine is running.

I'm not suggesting you go and look at things you might not know about, but some members have had issues with the main fusebox in the engine bay. This is the 'big boy' where all the vehicle high current is fused and routed. One member found theirs melted, most likely due to dirty connections on a high power fuse holder which had gone unnoticed. ABS plastic is a good low voltage insulator, but melts easily if it is allowed to get hot. Once it burns and chars, it's no longer an insulator. There's also a couple of BIG and very important chassis grounds sitting under the fusebox (or was it the battery box?) that can get corroded. One of them is for all the fat brown ground return wires in the loom.

This type of faults is worrying because if the main starting and ground cables have bad connections, the starter could pull current through the loom ground wiring. This hypothetical fault scenario could be as you describe and its the whole car ground wiring getting a raised voltage potential during starting and after the system modules have been self checked that could cause some regulator modules to shut down. The car can still start but the starter is taking its current from the wrong wires. Diagnostics won't tell you this, it will just put up a bunch of faults. V.W try to keep the main loom grounds separate from the battery starter ground to prevent this happening. But some do aftermarket mods attaching wires to the battery terminals and screwing down this and that to the bodywork. Once this is done, it destroys the loom protection designed in by V.W. That's why a decent auto electrician may charge £90 because if this is the problem and you keep starting and running the car, it may impact on control modules and the wiring loom.

More testing revealed some weird electrical controls . The front window switches started to operate the back quarter windows. Wipers & washers stopped working indicators erratic, however after removing the glovebox to gain access to the control module, I noticed that the wires were quite stretched at the plug in socket after a bit of pushing & pulling the controls starting working in the right order when the ignition is on. The only thing not working is the rear right quarter window which just might be a faulty switch. Rear boot electrics are also working again. I shall put everything back together before I risk starting the engine. Fingers crossed. I shall keep report back if all is Ok.

 

[voxmagna]

Best to buy yourself an aerosol switch cleaner (and diagnostics!). Many cars left standing during COVID lockdown and wet weather can suffer similar problems with their electrical connections. The problem with that one, is an intermittent fault that's still there could stop your roof op. part way and leave you frozen out of the trunk or stuck when a dark rain cloud hovers overhead. Rear window problems are rarely simple switches. If you scanned for faults you would get a better answer. Onwards and upwards hopefully then?

 

[Ren 25]

Best to buy yourself an aerosol switch cleaner (and diagnostics!). Many cars left standing during COVID lockdown and wet weather can suffer similar problems with their electrical connections. The problem with that one, is an intermittent fault that's still there could stop your roof op. part way and leave you frozen out of the trunk or stuck when a dark rain cloud hovers overhead. Rear window problems are rarely simple switches. If you scanned for faults you would get a better answer. Onwards and upwards hopefully then?

Ah , too late I was testing all the electrics which are now working but unfortunately decided to test the sunroof & guess what, it has stuck in the open position. The motor is trying to close it but sounds like something has jammed it. Next job is to get headlining off when I read up on how to do it. Also raining now but fortunately I had a cover.
Wish I had a garage.

 

[voxmagna]

Bad things like that happen. You cannot 'Test electrics' on these cars and assume they are working without diagnostics support. Until you know every control module is error free before you press a button, your problems can go from bad to worse. Other things you thought you fixed with a push and a huff on plugs and wires, may come back with faults in other areas. Have you got the rear windows working correctly because that fault alone will stop any roof operation and it's the same for the sunroof. Imagine you are out on the road miles from home and it's your roof stuck half open. Your cover buys you a little time until it sags under the weight of rain water, only to pour over the leather seats and transporting your dead EOS safely with a tow truck becomes a challenge. I sometimes wonder if V.W should have sold the EOS with a popup gazebo instead of the warning triangle.

 

[Ren 25]

Bad things like that happen. You cannot 'Test electrics' on these cars and assume they are working without diagnostics support. Until you know every control module is error free before you press a button, your problems can go from bad to worse. Other things you thought you fixed with a push and a huff on plugs and wires, may come back with faults in other areas. Have you got the rear windows working correctly because that fault alone will stop any roof operation and it's the same for the sunroof. Imagine you are out on the road miles from home and it's your roof stuck half open. Your cover buys you a little time until it sags under the weight of rain water, only to pour over the leather seats and transporting your dead EOS safely with a tow truck becomes a challenge. I sometimes wonder if V.W should have sold the EOS with a popup gazebo instead of the warning triangle.

I agree. I bought a hardtop convertible thinking that it would be better than a soft top if kept outside in the winter. I guess I was wrong. I have just seen a video of how to close the sunroof manually .At least it will keep the rain out.
The rear window will go down if I swap over the switches & goes down with the full windows opening switch so the motor is Ok. Another day in lockdown with time to spend working on the car. Does anyone remember the old VW advert which stated : If only everything in life was as reliable as a Volkswagon? mmm.

 

[voxmagna]

It's rarely motors causing problems because they are electronically overload protected and so strong they can break other parts first.
If the sunroof motor jams and protects itself (by stopping) then forcing a manual close can do more damage. But YT videos don't tell you that.

VW advert which stated : If only everything in life was as reliable as a Volkswagon? mmm.

That would have been the old classic air cooled Beetle. You can have one of those in a rag top and there will be very little electronics to challenge you. You wind the windows up and down by hand - no wires or switches.

 

[Eralov]

It's rarely motors causing problems because they are electronically overload protected and so strong they can break other parts first.
If the sunroof motor jams and protects itself (by stopping) then forcing a manual close can do more damage. But YT videos don't tell you that.

That would have been the old classic air cooled Beetle. You can have one of those in a rag top and there will be very little electronics to challenge you. You wind the windows up and down by hand - no wires or switches.

I’m sadly learning that the old classics aren’t as simple as that. We retired the 80 rabbit convertible for the eos. The rabbit needs a new wiring harness. It is parked until restoration is possible. I got the eos, because it was simpler. Until I have problems!

 

[voxmagna]

I understand, but at least you don't get stymied with microprocessor systems and chips you can't fix. Most didn't have ECU's then and most parts were electro mechanical. I was always fascinated by the way they did the dynamo voltage regulation and the sparking experience you got as their relays opened and closed.

 

[Ren 25]

I understand, but at least you don't get stymied with microprocessor systems and chips you can't fix. Most didn't have ECU's then and most parts were electro mechanical. I was always fascinated by the way they did the dynamo voltage regulation and the sparking experience you got as their relays opened and closed.

No overnight battery drain & most of the electrics are still working correctly with the exception of the rear window & sunroof. I removed the headliner & plastic cover. The cheap plastic cover is very flimsy so does need extra care when removing. I broke mine but I do have a tube of araldite somewhere. I managed to turn the roof forward manually to make the car watertight, It was quite hard to turn the mechanism. The whole roof was dry & no sign of any leaks. I aim to lubricate the cables & drive wires but the plastic cog is well damaged so will need replaced.
I remember the days when you could remove an engine in a couple of hours with the help of a few friends with beers, then rebuild it & have it back in the car the next day.

 

[voxmagna]

I aim to lubricate the cables & drive wires but the plastic cog is well damaged so will need replaced.

The cog failed because of too much friction. I hope lubrication works for you. It doesn't always.

 

[Ren 25]

The cog failed because of too much friction. I hope lubrication works for you. It doesn't always.

I also noticed the ground wire under the front left headlight had a bit of corrosion which I cleaned with some sandpaper. As many have mentioned before, it is always good to check those brown wires for bad connections.