Strange going ons with my dash lights

[MidLifeCrisis]

No, I left the dash in. I suspect I've done a bad crimp.

E D I T: would that actually result in the strange behaviour I'm getting though? Just to double check.

As others have said it sounds like your dash gauge cluster no longer has a good ground connection.
Without a correct ground connection the dash will 'try' to ground through the high beam warning light which might explain why things change when the high beam is put on.

[danmetallic]

All solved! A combination of things I think.

One or two crimps needed redoing. Plus there was 3 earths still with their old spades (which looked fine at the time). I replaced these with new spades also and everything was fixed [SMILING FACE WITH OPEN MOUTH] This maybe effected the resistance.

Thanks for the help!

[ZsZ]