I have quad rounds with 9004's on the 7" light. I took the bulb out thinking it would need to be replaced and was surprised to see they were in great shape. So, it's the housing. Is the lens [or housing I guess] all glass? Can I pour water and ammonia in it to do a good job cleaning it? What have you all done, let me know..
Are you sure it's the lens that is fogged up? Maybe the lights are dim because you have postive voltage to the lights but your grounds are poor. Easy to check . get a couple of wires with some connectors that will fit directy on the bulb connectors, touch the wires directly to the battery.
If it is your lens's then get some windshield polish from a car parts place -3M makes such a product or try soem fine polishing compound
Can you see in the lights? I'm wondering if your dim lights are not connected to a wiring issue if the reflector could be buggered up.
I'm thinking you have a wiring issue though.
I'm going to go with the positive lead over the ground. If both lights are dim chances of having both grounds bad at the same time are rare. Not imposable though.
Have you checked for voltage at the plug? What are you getting?
Have you checked for voltage at the plug? What are you getting?
You should check the voltage at the lights with the lights on (under load)
Being an A2,..
I'd guess it's the headlight switch,... dropping too much voltage, probably getting hot.
Relay the headlights, center lights too.
Even the tail lights draw hard on the headlight switch,.. my tail lights were bad and I traced it back to the switch.
Mk2's light harnesses aren't the best, sadly.
I would check the headlight switch and wires (as fatmobile already sugested), and the lock switch on the steering column. All light amperage passes through a tiny metal contact and it may melt the plastic.
A couple pics:
(The one circled in red)

(Close up of the melted plastic)

In that case you should change the inner switch inside the lock thingy.
I will second getting relays wired in. By the time the electrickery has gone all round the houses, through the verdigrised copper and cooking chocolate headlamp switch, back around the houses you will be lucky to see 9volts at the bulbs, most likely less. The standard wiring is crap. :evil: