Passenger side headlight and fog light dimmer then drivers side ?

[candymancan]

Just curious if anyone would know why the passenger side headlight and fog light would be dimmer on the passengers side then drivers. I mean my lights are bright. But i noticed when i left ny lights on by accident.. one side was dimmer then the other.

The fog light bulbs and headlamps are 4 years old now. The lights are the sylvnia silverstars i believe the brightest one they had which said theyre only good for a year if i remember.. so im sure the fillament is getting old.. But it seems odd how both fog and headlight are not as bright on the same side

[sirrus]

With headlights wiring goes to drivers side first and then to passenger side - extra resistance would make lights dimmer. So I'd look for bad ground connection (I think it's below coolant or washer reservoir on drivers fender) or corroded connectors. IIRC fog lights share ground points and power supply with headlights