Headlights
"Let There Be Light"

by Mike C.  Technical Index
Have you paid any attention to your lights lately?  Really, do both your low beam and high beams work?  Does the road before you seem like it was a bit dimmer than last night?  I bet you haven't touched those headlights in 10 years!  Let's take a look to see what you need to see the light again.

The first thing to do when checking to see if all parts of the headlight system work is to check the
fuses under your dashboard.  I know that is not the most obvious, but it is the simplest and cheapest way to make sure the lights are working, as the headlight circuits go right through the fuse panel.  Check your wiring diagram to see which fuse is which, or just look for the metal strip on the fuse to be severed in two, which would indicate a blown fuse.  Go ahead and replace it anyhow (with the same amperage
fuse, of course) and check the results.  It either solved the headlight problem or another problem altogether.  If that didn't solve your headlight problem and the new fuses didn't blow again, then you probably have defective headlight bulbs.

Most of the time when headlights go bad, they either fail on the high beam only, the low beam only, or the reflective surface inside is badly worn
to the point where the brightness of the lights is greatly reduced.  If a rock hits the headlight lens and cracks it, moisture can seep in and cause the reflective surface to deteriorate over time, even if the bulb won't burn out.  To replace headlights, you will need:  (1) or (2) replacement headlight bulbs, a medium-sized phillips screwdriver, and some WD-40.
1.) Start by removing the one phillips screw that holds on the headlight trim ring. 
2.) Slide the ring a bit up and off the fender. 
3.) Now remove the three phillips screws that hold the headlight retaining ring to the headlight bucket. 
     Careful, don't lose these tiny screws! 
CAUTION:  Also, be careful that you are not undoing the headlight aiming screws that are a bit behind the retaining ring.  The retaining ring has three tabs coming off of it that the tiny screws go through.  That should help identify them if you are not sure. 

4.) When you have the retaining ring off, the headlight will fall out. 
5.) Pull the connector off the back of the headlight bulb. 
6.) Squirt a little WD-40 into the connector contacts (credit to Herschel D. for this one) and the WD-40 will remove some of the built-up corrosion and further protect it from any more future corrosion.  This will make your headlights burn brighter as a result.  This especially helps on a 6-volt system. 
7.) Take a new headlight bulb and push the connector onto it. 
    
NOTE:  The correct way to put the bulb in is to install it with the lettering on the bulb in an upright and readable position.

8.)  While holding the bulb in place, slip the retaining ring in place, lining up the tabs to the screw holes.  If your screwdriver is magnetic at the tip, it will make the job easier. 
9.) Put those tiny screws back in the retaining ring.  It can be a bit tricky to fumble with them, so don't lose them. 
10.) Now put the trim ring back on and do the same for the other side if you are replacing both bulbs.
There are many different types and styles of headlight bulbs available these days.  You have the standard sealed-beam, halogen sealed-beam, halogen with lens and bulb as separate items (Hella H4 for example - I personally like these), and those funky blue and green colored lights that are supposed to look like the HID lights on Lexus and other expensive cars.  Whatever you use, be sure to use them in matched pairs or you'll have widely-different brightness and color variations from side to side.  You sticklers for originality will want to pick out the standard sealed-beam.  If you don't mind the whiter light and want more output that the halogens provide, then that is the way to go for safety's sake.  The halogen bulbs are more expensive, and the separate bulb-and-lens setups such as the Hella H4 can run you $50 or more per pair but are worth it for their greatly increased light output over stock.