Fixing headlights not difficult

Dear Mike: I have a 1995 Dodge Intrepid. The headlights are really, really bad, especially when it’s raining at night.

How can I fix this?

— M.C., via e-mail

A: Popular Mechanics had an Intrepid in for a long-term test around 1995 — and I recall writing in my report that the car’s headlights were substandard, particularly on rainy nights. So it’s not your imagination.

If you have pitted or frosted headlamp lenses, you may be able to polish the surface to resuscitate them for a season or two. If the internal reflectors are corroded, the lens assemblies will have to be replaced. Just the parts to do that will come to over $275.

If those parts are OK, and you’re simply unhappy with the light output of the headlamps like I was, you can try substituting a higher-output bulb. There are several manufacturers who make brighter replacements for the standard 9007 lamp. These stock halogen bulbs are rated at 55 watts low beam/65 watts high beam. Try an aftermarket bulb that claims improved brightness, rather than one that simply changes the color of the lamp to be trendy.

If that doesn’t cut it on a long, rainy drive, try upgrading to a higher-wattage lamp. Caveat: More powerful high-wattage bulbs generate more heat and may warp the composite plastic housing. They also draw more current and can overheat the wiring. Stick with 85-watt maximum bulbs.

Dear Mike: You published a letter earlier this year from an individual who needed to remove an improperly installed rearview mirror tab from his windshield. After spending a week with exactly the same difficulty, I asked the local repair shop.

They said they had a gadget to remove the tab and would be happy to do it for five bucks. The special gadget turned out to be a crescent wrench. Just put the wrench on the tab parallel with the glass, and twist. The tab will pop right off.

— F. C., Enfield, Conn.

A: This seemed so simple I had to go out to the shop and try it on a car. Slick. This procedure didn’t even leave any adhesive residue on the glass. Many thanks for the tip.

Dear Mike: I have a sprinkler system in my front yard that splashes water onto my car on breezy days. I think the water droplets that evaporate from the side-window glass leave mineral deposits behind. Oddly enough, the paint doesn’t seem to collect any deposits, nor do the windscreen or the back glass.

I’ve tried every window cleaner I can imagine, but nothing gets rid of these annoying stains. My son-in-law suggested I try using hydrochloric acid to dissolve them, but that really doesn’t sound like a good idea to me.

How can I remove these spots?

— Anonymous

A: Bad news: They probably aren’t mineral deposits. The glass has been etched by corrosion. Here’s the phenomenon: Your municipal water — or whatever water supply feeds the sprinkler system — may have a high pH (it’s alkaline, or a base), or you may have had some highly alkaline surface dust on your glass that dissolved into the water.

This high-pH water then slowly dried in the sun. As the volume of water decreased, the concentration of minerals, and consequently the corrosive quality of the solution, increased. This could have etched the surface of the glass, leaving not a deposit, but a ring that is below the surface of the surrounding glass.

Worse news: You can’t remove these rings with glass cleaners or acid. You have three options:

•1. Get an auto glass shop to polish the surface of the glass.

•2. Polish it yourself. This requires a felt wheel, a variable-speed electric drill and a kit of various grades of cerium oxide abrasive. The procedure is similar to grinding and polishing a telescope mirror.

•3. Replace the glass.

Why didn’t the water also etch the windshield and backlite? They use a more durable, laminated glass. Most important, how do you prevent this from happening again? Keep the windows clean and waxed so the water doesn’t pool on the surface in big spots.

And, as an aside, the only acid I would suggest you try is straight household white vinegar. Put some on a rag and don’t let it dribble. Don’t rinse until it has dried, to avoid getting any acid into the door.