I have a mk1 facelift focus on an 05 plate which is continually blowing headlight bulbs.. They are only lasting a few months and then blow again

To start with I just changed the bulb that had gone but then the opposite one would go shortly after and after about 6 bulbs I replaced the pair at the same time with Ring super bright bulbs which lasted around six months but one has now blown..

Is this a common problem, can't seem to find anything about it anywhere?

I have just stared using the heated screen again and wondered if this could cause a surge when turned off and would a resistor help?

Any ideas appreciated

Mike

 

I checked the voltage at the bulb when the screen was turned off and it jumps to 16 volts and then drops down again so I assume this is the cause of the problem.

Does anyone know which resistor I would need?

 

I'd be checking the voltage regulator on the alternator. Are you also getting 16 volts across the battery?

 

Didn't check that, will try it when I am at work tomorrow.. Thanks

 

Just checked and yes I am getting the same across the battery when the screen is turned off.. I assume this is pointing to the voltage regulator?

 

I didnt have a heated screen on mine and it did the same thing, usually ont he side behind the battery tray.

 

myold 52 plate focus zetec used to blow bulbs every month or so , in the end moving to bosch performance bulbs sorted it , i put it down to shit halfords bulbs in the end