Hopefully someone here can help me out of an embarrassing problem.   I
agreed to wire up some spotlights on my brothers VW Taro.   Plan was
for them to be linked to main beam, in that they would be on with main
beam, but otherwise off.

I have wired several sets of lights like this other cars, and had no
problems.   I thought I was fine this time too, as everything seemed to
work as expected.   However when he turned the ignition on, the
spotlights also come on with the dim-dip headlights.  they go off again
with the dipped beam, and then on again with the main beam.

This seems to be something to do with the dim-dip function, but I have
no idea how this works, or what to do to fix the problem.

Currently I have a relay, with fused live to lights, and switched live
spliced onto one of the main beam feeds.

What does dim dip do to this feed?   How can I stop it?   is there
somewhere else (convenient) that I could pick up the switched feed
from?

Thanks in advance

Mark