One of the more common faults on Mk1 Fabias and similar is the breakage a couple of thin wires going to/from the alternator.

There are hundreds of threads on this forum about these problems, here's a link to a fairly recent one: http://www.briskoda.net/forums/topic/287467-load-signal-alternator-cable/

 

If the blue wire breaks, the alternator won't reliably start up and may only start up at higher revs, leading to low-voltage/battery problems.  Another thing that happens when the blue wire breaks is that the battery light no longer lights up in the instrument panel when you switch on the ignition. So the easy check to do, without even opening the bonnet, is to sit in the driver's seat, turn the ignition key to the position where stuff lights up, and see if the red picture of a battery appears:

 

 

https://dl.dropboxusercontent.com/u/90027371/Fabia/Battery%20light.mp4

 

It should stay lit until you turn the key further and start the engine, then it should go out.

 

If you don't see it, chances are very high that your blue wire is broken (if not both), and the place to start looking is where it reaches a plug/socket pair on a bracket low down on the front of the gearbox (some handy pictures in the thread linked above, and elsewhere on the forum/web).

The load signal/DFM wire is actually the other one, and when broken this tends to bring on various dash lights like the ASR one, seemingly always after exactly ten minutes of driving. 

 

Edited 17 September, 20178 yr by Wino

Thank you for your very timely help. I'll do these checks tonight when my wife gets back home. Is the car safe to drive?

Thanks paul

Yes.

Did this guide resolve your problem ??I have the same problem 

If you're asking me, I haven't actually experienced it, but many, many Fabia owners have.  Fixing these broken wires tends to be the only thing necessary to return to a fully working charging system.

Seems more common in the diesel-engine cars, possibly because of more engine movement, so more shaking of loom sections.

51 minutes ago, Fabiamk1guy said:

Did this guide resolve your problem ??I have the same problem 

Well, it did resolve mine. Of course, I was about 99% certain that was the issue when I switched the ignition on one morning and the battery light didn't.

What amp cable is best to use on this 

 

As thin as you like.

The blue wire carries about 50mA max. if I remember rightly. The other wire is only a digital signal to the engine ECU, so will be even less.