My car's headlights have a problem!

February 6, 2009 3:12 PM

What is going on with the headlights in my Dodge Neon?

My 2003 Dodge Neon has a little problem. As of this evening, the headlights only work on the high beam setting. Low beams: both dark. High beams: both fine. A person who answered the phone at the dealer's service department said that 90% of the time when this happens it is a result of both of the low beam bulbs burning out at the same time. That seems weird. Could there be another explanation?

posted by longsleeves to travel & transportation (8 comments total)

Seems more likely that you'd have a problem with the light switch or a fuse.
posted by foodgeek at 3:19 PM on February 6

Chryslers of that vintage often have a fuse that controls only one half of the circuit (IE: both high beams or both low beams). The fuses are in the fuse box under the hood (next to the battery I think).

However it is extremely common for the second bulb to burn out shortly (within hours up to a couple weeks) after first burns out.[1] So much so that I always replace them in pairs. Also I've found it is pretty easy to not notice one bulb being burned out if you don't drive anywhere without street lighting.

[1] This makes sense when you think about it. The bulbs were probably made within seconds of each other at the same factory. Since being installed they have experienced the _exact_ same duty cycle.
posted by Mitheral at 3:25 PM on February 6

Are you sure they both burnt out at the same time? A single headlight out will often not be noticed by the driver. I know from recent experience. I think it's likely one burnt out without you being aware of it, then sometime later the other one did.
posted by ShooBoo at 3:30 PM on February 6 [1 favorite has favorites]

It's pretty common for the surge from one bulb blowing to knock out the other one. Not unknown at all. Just replace the bulbs and see what happens - it's an easy job. Come back and we can start to suggest more in depth stuff if that doesn't fix it.
posted by Brockles at 4:06 PM on February 6

Have you tried replacing one of the bulbs? That seems like the easiest thing to rule out...
posted by qvtqht at 4:10 PM on February 6

Could be the headlight relay too. The high beams will be on a separate circuit. On my Mazda you can hear an audible click under the hood when the relay engages. Have somebody turn on the headlights while you have your head under the hood. If you hear the relay engage, it's probably good. If not - might be worth replacing the relay first as it's probably a lot cheape than two headlamps.
posted by COD at 4:23 PM on February 6

Pull a headlight bulb, look at it. If one of the filaments is broken, replace it and go on to the other! If not, start looking elsewhere as people have suggested. Really, you can diagnose this with an eyeball.
posted by fritley at 5:45 PM on February 6

Now that it's been mentioned here, I realize it's possible that one of the lights has been out without me noticing it although I think I would have noticed. Thanks for the ideas and suggestions, I'll definitely be trying some things suggested here tommorrow.
posted by longsleeves at 5:45 PM on February 6