At 09:36 PM 9/28/2009, Mike S wrote:
>My understanding is that the constant blinking is caused by a leaky
>cap. It is probably just there as part of an RC circuit so the LED
>blinks for a bit at power-on.

Yes.  To the best of my knowledge I'm the person who discovered this,
before I was on the list I think -- early '90s.

>Perhaps simply removing the old cap will allow proper operation,
>except for that power-on indication.

Actually I believe that removing the cap will force blinking forever
-- the reason it fails to stop is that internal and external leakage
prevent the cap from ever charging enough to trigger the
shutoff.  Why VW used such a high-impedance circuit is a mystery to
me, unless it was to save a few cents each on the capacitor.

But the cap is really no problem -- the issue is that you have to
disassemble the gauge to get to it, and then put it together
again.  Small work, fairly heavy and also fairly delicate desoldering
and soldering, drilling out rivets and replacing them with ?#2?
nuts/screws.  Not hard if you're used to that sort of thing and have the tools.

Yrs,
David