The left hand high beam, park light and reverse light on my TJ are not working - bulbs are fine, fuses are fine. Any ideas?

A bad earth somewhere, perhaps? Check you are getting voltage at the bulb holders and at the appropriate fuses and relays. If you have voltage at the bulb holder (with lights on, test contacts to earth) it has to be a bad earth or globes that look ok but aren't.

Thanks. I'll have at look at that on the weekend.

Cheers.

Hmm, the following are the fuses/relays in engine bay:
Taillamp - #2 - 10A - Red. This is also the parker and rear combo lamps etc. #1 should be spare, swap it over with #2 to test.
Hi beam - #5 and #6 - 10A - Blue. Swap #5 and #6 to test.

There is no dedicated reverse light fuse. It is all in #2.