whats wrong with my headlight

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1969dodgedartgt

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ok, so my drivers side headlight stopped working the other day. I figured it was burnt out and ordered some new GE nighthawks or some such thing from amazon. But just the other night the light came back on, for that one night. I just looked at the wiring chart and it looks like the passengers side wire goes through the drivers side. I dont understand why the passengers side would work and the drivers not, unless its burnt out, but it apparently is not....

any clues?
 
Try cleaning the plug on back of light,apply a little Dielectric grease on connection.
 
It is burnt out replace it. Vibration will sometimes cause the two sections of filament to touch each other and the light will start working again. This will only be a temporary situation.
~Michael
 
You might also want to take a look and see if one of your ground straps broke loose. It can cause one side to be dim or off.
 
My guess ,one of the L shaped metal male spade contacts is broken away from that bulb or otherwise disconnecting. There are 2 wires in each of the 3 female terminals of the left harness connector so the right would still operate evn if the left bulb was completely removed.
 
Can't remember but I think the dimmer switch has separate wires to each bulb, check that.
 
My 65 harness has a short ground wire to a screw just behind each headlight that serves both lo and hi beam filaments. I got an engine harness from a 73 Dart at PickNPull for making a new harness. Those run a dedicated ground return wire, which seems like a better idea. I don't know if this mod was because the local grounds were problematic or the 73 didn't have metal to connect to (fiberglass front?). Anyway, ditto the advice to check your ground.
 
Just run a ground loop picking up the two factory grounding conductors behind light buckets, and run back to the battery. Use #14 gage wire. While you are at it, pick up the parking lights as well. Relying on factory grounds utilizing body metal in a forty year old car does not always produce good results.
 
x2 on the filament idea. Buld blown but as you drive the 2 piecies touch and work for a little while. Turn on your lights then tap on them (while parked of course). It will probley flicker.
Or switch the lights and drive a while and see what happens. Till your new blub comes in...
 
If the either headlihgt bulb is working at all the single factory ground attachment is obviously good. I dont think it will be nesessay to do a lot of re-engineering the electrical to repair a bad bulb.
On the other hand.. If you are installing modern bulbs that draw more current than the originals, you probably will end up re-engineering the headlights power supply. Much more than the chassis ground too.
 
Check the headlight fluid. I bet it's low.
 
Chrysler saw fit to use conductors barely of sufficient size to carry lighting load when car was new. You will find the eight inch grounding conductor serving headlights is one wire size smaller than the feeds to each filament. With age, that ground connection degrades from chasses, body weld, and fastener corrosion. The headlight bulbs on the shelf today draw more amps than the ones original to a forty year old car. So just using today’s lowest draw bulbs, the circuit is under sized.

By improving equipment grounds to lighting, the lights will receive closet to design current flow, and lights will burn brighter. The next upgrade step is to run headlight supply via two relays triggered from headlight switch, and powering lights from battery or power lug on alternator.

There is some disagreement to the correctness powering from alternator, but Dan Stern Lighting instructs that this is acceptable practice for these vintage Chrysler electrical systems.

I have made this upgrade on my 67 Dart, and the headlights are considerably brighter using run of the mill halogen sealed beams, and a huge load has been removed from the headlight switch. Next step will be to upgrade my bulbs.

All that being said, I agree that the filament has most likely broken, than it has temporarily healed its self from a bump, and will soon fail for good. This has happened several times to me over the years.
 
I think it was the fluid... changed the bulbs tonight... all better
it only worked that one night, when I had a long drive to make.... then the spirit leaked back out... only there when needed.
 
Is the fluid a dealer only item? I cant seem to find any at my local parts store.
 
Slantsixdan is our local headlight guru if your in the
market for an upgrade or would like some info.

He might have some fluid on hand.
 
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