Headlight motor turn on automatic ?

[laser]

When I put in key suddenly the "Headlight leveling motor" turn on and continued so, I had to disable battery cable to stop it.

Then I put on battery cable and its normal.

When I put in key again the "Headlight leveling motor" turned on again and continue so I had to disable battery cable again.

I took away Headlight assembly and dry with hairdryer, but same problem.

What can be the problem, control unit for leveling motor or leveling motor or .... ?

Volvo V50, 2006