does anyone know what might be causing the following problem, when i have the low beams on the right hand side only the park light comes on when i put them on high beam the low beam bulb comes on but the high beam bulb doesn't (left hand side is fine) ?

Id be first putting in a new globe and seeing if that solves the problem. To me sounds like the low beam filament is blown but the high beam filament is ok and your mistaking the high beam light as the low beam.

already changed bulb and it made no difference must be something else

Yep the low beam globes have two separate filaments... One does low beam and it switches off and the other comes on for high beam...

So if you reckon the globe is fine check for power in the plug... One of the three wires will be earth... One will be powered with low beams on and one will be powered with high beams on...

If you have the two powered wires working then it has to be globe, if no you get to chase the wiring for a break...

Cheers,
Tim

First check fuses in underhood fusebox -
24 = low beam Right Side
25 = low beam Left Side
15 = Hi Beam Left Side
16 = Hi Beam Right Side

if ok check circuits at lights -
black wire = earth
Red/Black = power when low beam is on
Green Orange = power when Hi beam is on

Note - relays are working if Left Hand is ok
did you check RH inner HI Beam globe as well as outer globe - wont affect low beam however