u/Deep-Moment2553

Recently bought a 2009 seat exeo with xenon headlights, after buying I changed both the bulb and the ballast as the headlight was either working with minimal output (maybe 5% compared to the other)/ not working at all and giving a headlight fault on the dash, anyone had problems with the connection on the headlight side from the ballast? Or any other thoughts as to what might be causing it to continue to fail? TIA