> Instead of going completely out, it's gradually
> slowing down.
>
> The other thing this is affecting is my engine
> performance,  as the computer needs the VSS
> signal (Motronic fuel injection) as my engine is
> a 2.0 Golf. I have a pick-up sensor installed in
> the back of the speedo that sends the signal to
> the computer.
>
> I am just asking before I remove the cable , if
> it might be in the speedo itself, or if the cable
> has broken and is slipping.

From the sound of it, the cable has become "rounded off" at one end or
the other and is slipping. If the VSS is running off a stock VW cruise
control pickup and it's affecting the ECU, then clearly that magnet in
the speedo is being spun too slowly (rather than, say, losing
magnetism). If I was a bettin' man, I'd lay money on the problem being
at the far end of the cable at the left front wheel hub.

Maybe time to upgrade to an electronic speedometer and an inductive
pickup at one of the inner CVs?

--
John Bange
'90 Vanagon - "Geldsauger"