Strange headlight

Well for the past couple of days I have been having a strange problem.
I switch headlights on in morning no probs, when I pull stalk for full beam it goes to sidelights only?? The main beam light flashes but goes out .
Pull stalk again they come back. After about 5 mins or so they work fine??
Sticky relay? Bad connection?
I tried a search but didnt find anything the same.

Cheers in advance

300 tdi M plate no extra lights or anything.

Light stalk - common problem.

Dirty contacts or need replacement??

normally burnt contacts - replace

Ok cheers will source new 1 then

Update !!!

Spot on MadHatMan replaced stalk today all working fine
Thanks very much.