Replacing a Headlight and Finding Corrosion

Generally, Adam is the one who deals with all vehicle issues (before Adam, my dad always fixed my cars).  Not only has he always loved working on cars, but he also has a degree in Mechanical Engineering.  But since my mechanic is 600 miles away, I was forced to figure out a minor car issue myself.

We just bought a '94 Dodge Ram 2500 Cummings Turbo Diesel.  Actually, Adam hasn't seen it yet.  I noticed that one of the headlights was out.  More specifically, the light that is the turn signal does not turn on when the other lights are on but blinks when the turn signal is on. That most likely meant that one of the filaments was busted.   Here is the side that isn't working:

The light on the right is the one that is not working properly.

 And the side that is:

If you look closely, you can see the faint glow of orange in the left light (that is working properly) in this picture.  

Luckily, the previous owners were very sweet to my new truck and my owners manual was in the glove compartment.  I drove over to the auto parts store in search of 3157NA bulbs.  It always seems like they never have the exact bulb we are looking for.  I got a salesman to help and he said 4157NA should work.  If not, I could bring it back.  By the way, apparently the NA means the bulb is amber in color and not clear, which is good to know.  I also picked up some bulb grease and I'm glad I did.

Removing the light was pretty easy.  Basically there is one screw holding it in place.

Screw located at bottom of light.

Then, you just slide the globe out of place by pulling it forward:

The just twist the globe off of the bulb and then pull the bulb straight out.

  Well, I realized that the bulb's filament wasn't busted; it was corroded. It isn't easy to tell from this picture, but the left connection is covered in nasty.

 The connection in the truck had just a little corrosion.  You can see the rust and blue discolorations on the bottom left.

I've dealt with battery corrosion before, so I tackled this the same way.  I grabbed some distilled white vinegar in a disposable cup, q-tips, and a wire brush:

Use the q-tips to apply the vinegar to the corroded surface.  To remove built up corrosion, you might need to use a wire brush to scrub it away.  After some gentle scrubbing, I added a little more vinegar to a q-tip and removed some more corrosion.  Lastly I used a dry q-tip to dry the area.

After Scrubbing

So, it is not perfect but it worked!  Now just lube up your bulb based on the packaging directions and slide it in.  Remember how I said I was glad I picked up some bulb grease? The bulb grease is suppose to help prevent corrosion (I don't think the previous bulb had any).  At this point, I made sure everything was working: 

Checking the light before re-assembling 

 To re-assemble, twist the bulb back into the globe.  Then you need to slide the globe straight back into the truck.  Mine has a piece that it needs to slide into.  It took me a minute or two to figure out exactly how to puzzle it back in.  Then all you do is replace the screw.

Oh yeah! Look at that orange glow.

This quick project took under 10 minutes and cost under $10.  $5.99 for 2 bulbs and about $1 for the bulb grease (which I still have a bunch left since I only did one bulb).  I used 4 q-tips and about an ounce of vinegar.  I think that adds only a couple of pennies to the cost.  I always have a gallon of vinegar on hand.

 When dealing with battery corrosion on a previous excursion, the interwebs had differing opinions on how to deal with corrosion.  Basically, the argument comes down to whether you need an acid (the vinegar, or cola) or a base (a paste made of baking soda and water) to counter act the acid corrosion.  I've tried both and the vinegar seems to work much better.  The science here is driving me craazy.  Logically, it would make sense for the base to neutralize the acid but it just didn't work.  It must have to do with the pH differences between the vinegar and the corrosion.  Do I have this completely wrong?  But, the wire brush does a good amount of the work, anyway.

There are also some products on the market to help get rid of corrosion, like this: CRC QD Contact Cleaner
But $16 for 11 oz seems pretty steep to me.

I'll let you know if the light craps out on me.  So far, so good.