I suggest you look on www.abvwc.org.uk to see if you can find a local VW club.
Arrange to go along to there next meeting, take your mulit-meter and ask them
about the problem.  Someone there might take a quick look, which could be all
it needs.
Oh, and get a manual for your car.  You would get one with the circuit diagrams
on E-Bay for not much more than the postage cost.   The diagrams are on several
pages, are different for the different models and the number codes for the
components are on another page, so it's not just one page to scan, otherwise I'd
oblige.

There is even a (ripped-off ?) dealership CD with all the stuff on it, for £2
but I've a feeling it's a USA version - not sure whether there would be
differences.  Maybe nothing on carbs?
Plus a (ripped off ?) CD 'Factory manual' - from a new seller with no feedback.
Hmmm...

Buyer beware, but there is no shortage of stuff on Mk 2 Golfs. eg item
200065785330 would cost £5 inc P&P at the moment.