Side lights work but when swithing on main kills all lights?

[Leepylaad]

Hello again people ive finally rebuilt my nsr 125 ry and got her running sweet but im having problems with electrics. ( not good with electrics lol)
When i turn the key with light swith on off evrything is good i can star the bike, neutral lights on etc turn the switch to side light and still everything ok and sidelights come on but soon as i switch it to main beam all lights turn of around the bike and the clocks. Put ir back to side lights still nothing but if left for around 30 secs side lights and nuetral come back on?
Now the fuse is good connections are good the other thing i was wondering is there another earth besides the 1 off the ht lead that could need cleaning? Any help is apprectiated cheers guys
____________________
Any help is appreciated.