BarryB72

I got some original bulbs for my 72 and swapped out the working bulbs that were in it tonight.

Right now the driver side bulbs are fine but the passenger side only lights up on the outer bulb when the brights are on and the inner bulb does not work at all.

So the low beam does not work on low but it does work on hi, and the bright bulb does not work at all. Can both symptoms be connection issues?

Alan 71

Hi Barry,
Do you know for certain that the original headlight your using works?
Have you checked the condition of the connection of the copper 'prongs' to the bulb body?
Not being an electrician.... I'd test the bulb on the other side to see if it works there or not?
Regards,
Alan

BarryB72

Thanks for the reply. I actually bought 8 bulbs in total so I could feel ok using 46 year old bulbs --knowing I had spares. I tried 3 different bulbs in the hi beam location on the passenger side and none of them worked.

I will also try the newish sylvania bulbs I pulled out, but it was getting late and I had to clock out at some point last night.

I guess my real question is -are these things wired in any way that would cause my symptom, or is the most likely culprit the low beam has one prong not making contact so that's why it works on high but not low (and I'm assuming my hi beam is not making contact at all.)

Revi

If you actually have "original" 1972 bulbs, they are as rare as hen teeth. I wouldn't be using them except for some type of judging event. If you have original 1968-1971 bulbs, they aren't as rare, but I wouldn't waste them on everyday driving.

If your headlights worked correctly before the change, it's either the bulbs or you don't have the plugs seated correctly, pulled a pin loose or something along those lines.

Alan 71

Hi Barry,
Have you checked for certain that the 'prongs' on the lamp are properly seated?
Regards,
Alan

They can 'turn/spin' a little which might cause a bad connection?

henrikse

Do you have a meter or test light? Use one and find out if voltage is making it. You can compare from a working one to the other instead of swapping. If you have a problem you don't want to damage a bulb

D_Williams

If the wiring is the same as in '70, then I would say they are separate issues. Because the high beam works on the outer bulb, then the ground must work and the high beam wire from the floor switch is ok, and because the lights on the driver's side work, then the issue must be between the driver's side and the passenger's side lights (or you have been very unlucky with bulbs).

Edit: If the bulbs are not the issue, then my guess is that the issue with your low beam is between the driver's side and passenger's side lights and the issue with the high beam is between the outer and inner lights on your passenger's side.

BarryB72

The only tester I have is the kind that you use in wall outlets. Could that work?

Anyway, I see a lot of what I think is dielectric grease on the prongs of the lights I took out and some in in the plugs.

I'm going to clean up the prongs on these old lights to make sure I'm getting good contact and report back.

henrikse

No wall outlet tester is for AC only. You can by a cheap test light that has a metal pint on one end with a clear handle and bulb inside. There is a wire lead with a alligator clip on it so you can clip it to positive or negative to test circuits. Under $10 most places.
The dielectric is there to prevent corrosion so don't remove it.

BarryB72

Got the Sylvania bulbs out of the basement and they still work. Should have been my first test. Sorry, could have saved some of you from needing to post. I really was not wanting to deal with plugs or wires.

Guess I'll just start cleaning up these T3's.