My headlights!! :(

[Dylrobz89]

I was just driving home from work before, one of headlights hasn't been working for while, changed the bulb for a second hand " working " one, that went out a couple of hours after having it changed! anyways, it came back on while i was driving home before, stayed on for about 10-15 miles, Got home just now and its gone out again! Any ideas why?
Thanks
Dylan

 

[Josh@Renparts]

check for moisture where the ballast connector is.

 

[Dylrobz89]

Thanks mate, i'll check it in the morning, any other problems it could be ?