Author Topic: Mk3 Front Foglight  (Read 6735 times)

Offline DKnight

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Mk3 Front Foglight
« on: June 30, 2008, 04:20:09 pm »
disclaimer: if you break anything because of something you read here, it is not my fault. ok?

i bought some foglights from someone who'd had them on a car, but never wired them in or tested them.

I found that one side (right-hand side lamp) was spot-on, worked brilliantly, whereas the opposite side was dull and didn't seem to project much light at all in comparison.

i went and swapped the bulbs around - the bulbs were identical in spec and brightness so it wasn't that, confusing!!! as the beam of light was aimed the same on both lamps, they have the same bulbs, but one projected a significantly darker beam of light!

so, well, i started dismantling them! !

i noticed that the black one in the photos (my left one) got very hot to touch the casing (the black bit) whilst on for a short period of time, but the browny coloured one didnt get anywhere near as warm....

upon dismantling, you can see in the photos that the brown one has a layer of silver lining which acts as a light (and therefore heat) reflector/deflector (whichever!) so that more light is aimed at the lens and out through the glass...... although its silver, it isnt very shiny/reflective so can be improved!

everything on the foglights is the same on both sides except the obvious bits which are identical just mirrored as they are mirrored for the opposite side lamp.

tomorrow - i'll be getting some of that plastikote silver metallic reflective spray paint (as long as it doesnt warn about being used in hot environments) failing that i'll be bonding some tin-foil in. then i'll put them back together and take some more pictures and show the results!

basically, you can make your mk3 polo foglights better by making the backing (if your have any) more reflective!!!!

plenty of pics from dismantling below (all already with the bulb & holder removed)

the unit together (yes i know it doesnt look like a very good repair on the bracket, but its solid!)

if you dont want to risk breaking the adjuster trying to pop the black bit out, completely undo the adjuster screw (adjust it so far the screw detaches from the black bit), then pull the lamp housing away from the bracket (it may have blobs of glue around the square bit of housing)

the two halves and the water-tight seal

the unit in bits (in order) [note: you dont have to remove the glass, i did out of curiosity - be warned, they break easily!!! it is held in by the 3 metal lips squeezing the glass]

the metal braket that holds the lens in will prise out gently with a long screwdriver... put a screwdriver through the bracket to the opposite side, under the metal bracket between it and the plastic housing, and then twist it to force the bracket away from the plastic housing... or you could do it properly and remove the sealant from the four corners of the metal on the behind of the plastic , and lever the brackets straight... see below

as you can see from the reverse side after removing the rubbery sealant, the metal bracket could probably do with a blob of glue & sealant on it to stop any water getting in and to stop the lens holder from coming away from the plastic at any point in the future.

]notice that the brown plastic lens housing has a silver reflection ! this is the reflective backing inside where the bulb sits, and on the black one there is no reflection whatsoever.

when putting the units back together, i didnt think about what i was doing very much and pushed the metal bracket back on to take the pictures....
as the metal bracket clipped into place the pins shot through the plastic and i punctured my finger deep!!!! blood all over my desk. yukky!!!!! not fun! (bad times!) dont worry, no pics of the wound or the blood.

left side (darker one)
this one has a more scattered, darker beam from same bulb tested on the brighter lamp - dont forget the camera has left the shutter open slightly longer for this as the room was darker, i couldnt figure out how to manually set the speed so both foglights have a decent comparison

his is the spray i bought, £3.29 at halfrauds.... it looks dull, but silvery chrome coloured. the spot i did on the newspaper was very reflective when only just applied!!!

(edit: where a glove on the spraying hand...)

masked up, spend a bit of time doing this if you dont want silvery overspray on your foglights! small bit of newspaper scrumpled up in the hole where the bulb goes too will help

first coat (with no flash)

first coat with flash on

second coat flash on

the spray is a bit runny so more lighter coats = better than one big heavy spray.

more soon... waiting for it to dry a bit before next coat & to fill in all the roughness on the whiter one where the old reflector is scabbing off

i was so impressed with the improvement of the beam of light that came from the foglight after test-reassembly (wet paint still!!!) that i have also sprayed the lens bracket too, as this is also used as a reflector! (the metal work is very dull to start with )

be careful not to crack / damage the lens

lens bracket before spraying - clean it up as best you can with thinners / brake cleaner / carb cleaner, whatever. and make sure its dry!

finished article reflective bit - no flash and with flash

under side also needed painting - pic with flash

whilst waiting for the paint to dry.... been looking at the H3 Bulb HID kits, cant quite justify £100 on a hid kit just for the foglights....

this is the bulb without the new shinier lens bracket,

ignore the position of the light, all 4 of the pictures were taken without the outer lens on as its easier to stand them up on my desk that way!!!

Left side foglight : Before and After (the one that had no reflector in it)



Right side foglight : Before and After (the one that did have a reflector that i removed and re-did)


Thanks to Rae for this!
« Last Edit: June 30, 2008, 04:22:10 pm by DKnight »

Offline cheys03

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Re: Mk3 Front Foglight
« Reply #1 on: June 13, 2010, 10:53:13 am »
Rae, would it be possible to get the photos back?