39 dodge frequently burns out only the left headlight

[timmer117]

I have a 39 dodge two door sedan that cooks the left front headlight bulb frequently.  I burn them out in an hour or two of use.  When they are used the left one  turns yellow with a smokey film inside. Ive gone through 3 bulbs.  Any suggestions on what to do to correct this problem?

[ply33]

That is an odd one.

 

I guess I'd check for local high resistance near or in the bulb that might be getting hot and affecting the base of the bulb. But I associate short bulb life with an over voltage condition. I'd check the grounding between the engine and the body/frame and the grounding of the regulator (I assume that like Plymouth you have a 3rd brush generator with external voltage regulation). And I'd check the system voltage at several points like the output of the generator and at the light bulb socket.

[Guest DodgeKCL]

As Todd says it's almost impossible to burn out bulbs in this fashion unless there is more than 7-8 volts on the car's buss. Especially this quick. The bulbs will actually stand up to about 10 volts but will have a short life,but not this short. But the old mechanics that I've known always said 90% of their electrical problems arose from poor grounds not poor connections from the battery side. It is possible I suppose that poor grounding to the headlight bucket could be the problem I just don't know technically speaking how this would burn out a bulb. Temporarily take a thick connecting wire and connect it from the left bucket inside at the light socket and bring it out through the stantion and over to hood area and connect it "hard" to something that is obviously ground. If this stops it then your headlight bucket is "floating" away from ground electrically. I have seen lights in bumpers act up because the bumpers got away from ground. But it didn't blow any bulbs it just made all 4 corners of the car flash at the same time ,with one directional signal, as the bulbs sought ground through the other bumper and light sockets. You could be up against something just as wierd but it still shouldn't blow bulbs. I'm really interested in the final outcome of this. Please let us know.