Hi All,

 

64 plate Fabia 1.2TSI; Dash lights not working, no other electrics working except headlights. Had auto electrician out who diagnosed starter drawing excess current and a couple of battery top fuses blown.

Replaced Starter and complete battery top fuse board and car worked great for 3 days. Went to start this morning - same problem; no lights etc but fuses all have continuity and obviously starter is brand new

Any ideas whilst I'm waiting for the auto electrician to get back to me?

Forgot to mention - wont turn over neither! Thanks!

 

2 hours ago, Zuglie said:

Forgot to mention - wont turn over neither! Thanks!

 

 

Ignition switch failure seems the most likely culprit, hazard flashers working?

No - absolutely nothing electrical is working except the headlights. 

Probably this fuse:

 

 

May be an intermittent wire short from the output cable to ground? Follow the blue arrow to check as much as you can.

Edited 14 May, 20215 yr by Wino

No mate -  all of them checked for continuity, :(

 

I've just replaced all the battery fuses again, and turned the ignition key - ignition lights came on briefly, engine would not turn, then nothing. I think it is this fuse - what does it supply, is it the starter motor?

Will try and chase, as you suggest - failing that its into Skoda it goes..... :(

 

Starter motor isn't fused. 

 

That fuse I drew round carries current to many of the things inside the cabin. Described as "Interior voltage supply". 

80 Amp rated so whatever is killing it is taking a very large current.  Most likely a direct wire short to chassis. 

 

Update: put the car into Skoda and they found this, under the steering column. According to them not economically viable to repair and have been looking for replacement looms but only one I can find is in Germany.

 

Anyone spliced anything like this?

 

Very difficult to get to as it is to the rear, LHS of the steering column.

 

Thanks!

 

What's your location?

Doesn't look like many wires involved.

Liverpool.

 

Will be removing the drivers seat so I can get in and look at either removing the lower dash and/or steering column.

7 minutes ago, Zuglie said:

Will be removing the drivers seat

Good plan. Makes footwell-based work far easier, and takes very little time to do. Make sure you use the correct XZN bit, they're not Torx.

 

that would be easy enough to do a repair, Skoda just don't want to spend the time, they would rather fleece you with the cost of a new loom.

 

I would for a temp measure to continue diagnosis, just use small terminal blocks and bits of wire to add length where needed to "check" that it is the issue.......only then look at stripping back the loom to do a crimped or soldered repair.

Edited 27 May, 20215 yr by UrbanPanzer

Easy repair, difficult access, the sort of job that I would once have found easy but now with only one remaining longsighted eye is a nightmare for me.

 

I would look carefully to see if the loom has been pinched, perhaps by the steering column adjust mechanism, if not then its probably yet another example of the brittle wire that they are now using that cannot resist repeated flexing.

 

It looks like more than one conductor that is damaged.

Hi Guys,

 

Stripped dashboard out - quite emotional, and found the true extent!

Ive traced back to where the wiring seems in good health, and can effect an easy repair now.

 

My main concern is that the violet yellow wire, which the 3 red wires join into, when I do a continuity test to earth - I have continuity!

 

From the attached wiring diagram, this is a positive circuit - hence not good!

 

This violet/yellow wire goes to the onboad supply unit, (which I cant seem to fine!).

 

Thoughts/Comments greatly appreciated!

 

 

Regards

 

Andy

 

I can't see a violet/yellow wire in that wiring diagram? 

I'd expect the onboard supply control unit to be just above the accelerator pedal, I think.

The 3 red/black wires connect into it via the inline diode, of which I only appear to have an inline shrink wrap solder joint?

The brown/violet coming down off J811?

Has the diode failed short circuit, I wonder?

 

That would be horribly ironic, as I think its purpose is as a so-called 'flyback diode' to stop reverse-voltage spikes from the starter motor solenoid causing bad stuff to happen to connected electronics.

 

Edited 7 June, 20214 yr by Wino

Apologies!

 

Yes the Brown/Violet.

 

The 2 red wires, join together in 1. these are the ignition/starter wires

The joined 3 red wires, then join the violet/Brown wire via this solder shrink joint, as in 2.

 

I assume the diode is further down the line?

 

What concerns me is that the Vi/Br wire when connected to earth gives continuity and given that the red wires are a positive feed, this should not be happening?

 

Yep, the brown/violet is an earth connection, and that diode must prevent conduction from the wires connected to its other end.

The diode must be within that heatshrink tube that you've labelled '2'. The lump in the middle I think.

I bet that's what's failed, causing positive to chassis shorts.

 

Do you tend to let start/stop do its thing, rather than disable it each drive?

 

It doesnt have stop/start and if it does, its never been used!

 

There is nothing remotely like in my Kodiaq stop/start wise, i.e. no A button etc.

 

Its the wifes car, has just under 27k and the furthest its been is to the dealer and back for servicing!  (12 mile round trip!)

 

I will disect the heatshrink and see if theres a diode in there.

 

Cant for the life of me understand, why they would have positive wires connected to earth, and separated by a diode, unless its an overload thing?

 

4 minutes ago, Zuglie said:

Cant for the life of me understand, why they would have positive wires connected to earth, and separated by a diode, unless its an overload thing?

 

55 minutes ago, Wino said:

Has the diode failed short circuit, I wonder?

 

That would be horribly ironic, as I think its purpose is as a so-called 'flyback diode' to stop reverse-voltage spikes from the starter motor solenoid causing bad stuff to happen to connected electronics.

 

Reason I mentioned start/stop is that obviously if that were in use/fitted it would make the starter solenoid activity much more frequent.

Edited 7 June, 20214 yr by Wino

Definately a diode, and definatley fried -! 

On 27/05/2021 at 09:20, Zuglie said:

According to them not economically viable to repair

I bet they knew this was the problem, because they've seen it before, and they would know how extensive the resulting damage is.