Intermittent Battery Light - Turning Left or Right...

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slicker55
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Intermittent Battery Light - Turning Left or Right...

Post by slicker55 »

VW Polo 1.4 TDI (2008)

Battery and Alternator replaced to resolve charging issue - sorted

Vehicle stationery - steering wheel turned slightly left or right - battery light comes on / flickers intermittently

Vehicle stationery - steering wheel turned to full lock left or right - battery light comes on and remains on until releasing full lock

Performance of powered steering not effected

Any takers for this one please?
RUM4MO
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Re: Intermittent Battery Light - Turning Left or Right...

Post by RUM4MO »

You will need to check the integrity of the "excitation" wire and the "load sensing" wires underneath the car, round about where these wires pass through a plug and socket close to the engine<>gearbox joining face, these leads have their connectors fastened to the engine/gearbox by a clip at that point.
This is usually a TDI engined car issue, like you have, as these engines shake about a lot more than petrol engines and that causes these wires to break up/fracture, even if they are still just making contact, they could be fractured or at least most of the strands on the multi strand wires broken. Slice in new lengths of wire - maybe even ignoring the plug and socket.
slicker55
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Re: Intermittent Battery Light - Turning Left or Right...

Post by slicker55 »

@RUM4MO
RUM4MO wrote: Thu Jun 10, 2021 9:05 pmSlice in new lengths of wire - maybe even ignoring the plug and socket.
Thanks for taking an interest in my post - appreciated.

I have been working on the car all week and have spent many hours researching the forums and other online resources. I've got quite used to seeing your name and one or two other regulars kindly offering the benefit of their expertise to people like me and I am very grateful.

I am aware of the inherent issue regarding the break in the wires from the alternator at the location you mentioned. This was my first port of call and when I got under the engine, I quickly discovered there is only one plug present and it looks like someone has already repaired the other using two translucent pink splice connectors.

Now, I've owned the car from new and cannot account for this repair unless it has been routinely undertaken whilst the car has been in for service during the warranty period but I was never informed anything like that had been done - mystery!

So, a quick question for now... regular advice is to trace a break in either of the two wires (particularly the blue re. battery light not illuminating) but is there any point in further investigation when you take into account the battery light does illuminate in the circumstances outlined (steering turned either way)?

Appreciate all the advice I can get - the gauntlet is down and I won't be beaten :)
RUM4MO
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Re: Intermittent Battery Light - Turning Left or Right...

Post by RUM4MO »

Battery light coming on tends to indicate "charging failure" which could also include that the charging system is not maintaining the correct voltage output.

I would not 100% dismiss these already repaired wires, I would have expected that any repair would have included heatshrink tubing that contained a heat activated glue/sealer so that no moisture could get into that probably crimped repair wire joining part, if not moisture will get in there and cause issues like this again.

This is maybe a good point in time for you to buy a digital volt meter so that you can actually witness what the charging system is "doing" when this fault appears - also there are many cheap DVMs that plug into the ciggy lighter socket and only cost £5 - they are accurate enough to use in this instance, I've ended up buying one of them just to witness what the charging system is up to in my wife's 2015 Polo.

Of course this could end up being a power steering assembly issue, ie at times it is prompted to demand too much current, but not enough to blow its main power supply fuse.
slicker55
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Re: Intermittent Battery Light - Turning Left or Right...

Post by slicker55 »

RUM4MO wrote: Fri Jun 11, 2021 10:45 am I would not 100% dismiss these already repaired wires
Agree, I keep coming back to these wires and in particular the part which I can see has been previously repaired using the splice connectors you described. It has even occurred to me that whoever carried out this repair may have accidentally inverted the orientation of the wires.

Here's what I have at the moment...

The blue wire runs from the rounded side of alternator plug (which I believe is L) to a splice connector where it is joined to a lilac & green wire.
Tests confirm electrical continuity of this wire between the alternator plug and the ECU

The brown & red wire runs from the flat side of the alternator plug (which I believe is DFM) to a splice connector where it is joined to a blue wire.
Tests confirm electrical continuity of this wire between the alternator plug and the point where is enters the bulkhead on the engine bay side

So, in essence, on my car, the wire connected to the rounded side of the alternator plug is connected to the ECU?

Just for peace of mind, please confirm if this is correct
RUM4MO wrote: Fri Jun 11, 2021 10:45 ammaybe a good point in time for you to buy a digital volt meter
Good advice - already have a multi-meter!
RUM4MO wrote: Fri Jun 11, 2021 10:45 amthis could end up being a power steering assembly issue, ie at times it is prompted to demand too much current
A bit of an update here...

I previously reported that when stationery, engine running, turning the steering wheel causes the battery light to flicker. (tested many times, no particular wheel position, repeatable, but no specific pattern).

But, yesterday, I took the car for a test drive (16 miles) no driving issues...

The battery light did not come on until I started switching things on... then, it would intermittently flicker and extinguish as the additional load is introduced.

I know some might immediately suspect the alternator but I think the 'ignition on, engine off, no battery light' scenario is a major clue?

Please bear in mind the original Bosch alternator and Bosch battery have been replaced with identical new parts - there was a charging problem prior to replacing the alternator which the new one has now resolved.
RUM4MO
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Re: Intermittent Battery Light - Turning Left or Right...

Post by RUM4MO »

I thought giving you an answer wrt the wiring was going to be easy, I checked in my Hayes manual for 6R Polo and one wire is BLUE and it connects to BLUE, the other wire is BROWN and it connects to VIOLET/GREEN.

Edit:- so I know that your car is an earlier model, but there is a trend here, and that is BLUE connects to BLUE, which going my logic means that your repaired wiring is the wrong way round.

No battery light on when the ignition is switched on and the engine has not yet been started does normally indicate a broken wire - or in your case swopped over wires.

Battery light coming on when the load has been increased indicates that the alternator is not able to sense the increased load - again either a broken wire - or in your case, swopped over wires.

Okay faulty alternator can also cause some of these issues, but the facts as handed out by you are stacked strongly towards a garage having carried out a messed up repair.

The correct heat shrink tubing to use in that area, gets called "atomic tubing" - it has a sort of heat activated glue/sealer coating the inner surface and that creates a water tight seal when you heat the tubing up to shrink it.
slicker55
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Re: Intermittent Battery Light - Turning Left or Right...

Post by slicker55 »

@RUM4MO

Thank you for taking an interest in my posts - your involvement has been very inspirational and encouraging

I am very pleased to report that I have now resolved the issues...

The charging issue was due to a faulty alternator.

The battery light issue - ignition on, engine off, not illuminating - was finally traced to two translucent pink splice connectors which had been used to replace the original OEM block connector.

This car has been owned from new and has a proven full service history.

I cannot say when or by whom this wiring repair was undertaken but I do know that whoever carried out this repair inadvertently crossed the two wires.

I'm sure you will be aware of the following information but for the benefit of those who don't, the alternator plug contains two wires.

The DFM wire goes to the ECU and L wire goes through the bulkhead eventually ending up in the instrument cluster.

After correcting this wiring error - problem solved
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