Headlights... +

This section has info on anything related to headlights, topics are :
Cloudy headlight repair / Leaky Headlight repair
Headlight Switches / Blinking Fog Light Repair

If you have comments please E-mail me at: SPARKPLUGS@MAILCITY.COM .

These tips are only for the 1987-up plastic headlight assemblies that use the 9004 halogen bulb.


Cloudy Headlights
Have your headlight lenses turned yellow & cloudy?
Mustangs Plastic Headlights will cloud up with age. An inexpensive solution (other than buying a new headlight assembly for over $100) is to polish the plastic just like you would to oxidized paint


Do not use harsh rubbing compounds or abrasives on the plastic lenses, they will only scratch the plastic & make it worse.


I came up with a fix for the severely clouded and yellowed headlight lenses on my '91 GT, while waxing my boat. Everyone I spoke with said that I'd need to replace the headlight assemblies to fix the problem.

I figured I had nothing to lose, so I tried polishing the lenses with fiberglass boat cleaner/wax. I used West Marine brand, not sure it really matters, just don't use fiberglass cleaner for heavy oxidation removal (it's too coarse of a polishing compound). A soft cloth, a little polish, and some elbow grease made my headlights look and work like brand new again.

I did this about two months ago and have had no problem with the polish base discoloring or clouding up. If you have this same problem and no other fix for it, give this a try, $8.00 for a lifetime supply of lens polish beats the heck out of the price they want for headlamp assemblies.
... Contributed by Steve W.

I have also heard that using Mother's (or any good brand) Plastic Polish will work ...Spark Plug

INSIDE ? ? ?
It may be possible that the plastic lens is cloudy due to film on the inside of the plastic headlight. Some are skeptical but if I followed their advice I would of polished through the lens & through the engine block. That's why I suggest to look inside as well if you can't clear it up from the outside... here's what happened to me & might help you...
I removed the headlight assembly to caulk the seams, to stop it from turning into a fish tank & blowing out halogen bulbs. First I rinsed it out with water to get the broken bulb pieces out. Then I noticed that a green fungus had grown inside it on the edges. I filled the headlight with bleach & water & let sit for 15 minutes. After rinsing, the headlight was clear. Apparently the yellow-green stuff on the lens was on the inside. As the lens filled with rain water or condensation, a fungus grew & covered the inside with a film that clouded the light.

Leaky Headlight Repair

If you are getting water & condensation in your plastic headlight assembly & most likely blowing lots of halogen bulbs, it's time to reseal it. Removal of the assembly is not too hard. You must remove the outermost orange side-marker & loosen the inner one. There are 2 nuts on each side-marker to remove. The headlight has 3. You may have to go under the car & reach up to the nuts to get at some. Be careful not to damage the radiator.

Once you have the headlight out carefully pry off the metal bracket that holds the hard black rubber (it's a cosmetic piece only) to the lens. Then clean the assembly out with water. This should also show you where it's leaking from.

Use Outdoor/All weather clear caulking (obviously make sure it adheres to plastic). Put a thin layer where the lens meets the body of the assembly. Keep it thin, press & smooth the caulk with your finger so it will not be noticeable. Let it dry.

Put the metal & rubber bracket back on & install headlight "inside" of the side-markers. Look at the headlight you didn't touch, notice how the rubber is sandwiched between the side-markers.

Blinking Lights
This problem affects '87-'93 Mustangs GT's & Thunderbirds.

These cars were built with a week wiring system to power both headlights & the fog lights.
Resulting in fog lights & usually both headlights & fog lights blinking on & off when fog lights are on. Another possibility is that the plastic wire connector to the high-beam switch gets burned & melts & doesn't do you any good.

Fortunately All you need are a few inexpensive items from Radio Shack & and hour to solve this. The easy repair is solved by The Corral Web site (corral.net), it explains this fix in detail with photos & easy instructions. It includes the addition of a relay & will now make it possible to have the fog lights on without having the headlights on, Just remember to shut them off. The Corral is listed in my links page which is full of excellent tech related sites.


Turn Signal & Highbeam switch info
Due to finding that others suffer from the below problem in 87-93 mustangs & Thunderbirds
I wrote this to help others who might need it...

Ever drive around with the headlights & fog lights on and smell burning plastic? It seems that the plastic headlight wire harness plug that goes into the turn signal switch gets hot & burns out, or something else out. Usually affected by the "normal" fog light blinking due to inadequate wire & relay.

I smelled burning plastic & shut off my fog lights. The smell stopped. I filled my high beams on only to break the insides of the highbeam switch. While the harness melted it must of heated an internal switch part which made it week.

Burning plastic smell, headlights don't work, possible switch cracking internally.

Either solve the fog light problem (go to my links section for site with instructions.
Or disconnect & never use the fog lights.

Not sure what a new switch goes for but you can pick one from a junk yard for around $45 .



You do know not to touch the glass of the halogen bulb right? Since they burn much hotter than regular bulbs, oil & dirt from your hands will heat on the glass & break it. Handle the bulbs only from its plastic base.
1987-1993 Mustangs use # 9004 Halogen Bulbs.
Coming Soon here(late October 99?)...bulb chart with #'s & location diagrams.



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