The Stovebolt Site Forums The Shop Area The Electrical Bay smoke in the head light

2 things 1- I'm using the original 6 volt head lights. Got the new wire harness run and i'm testing all things electric. Pulled the head light switch and they did come on. But, inside the glass I saw smoke or fumes. Why are they smoking is my first question. Second,the gas gauge showed a full tank. I only had 5 gallons in the tank. I forgot to ground the gas tank. The gauge shows a empty tank after the ground was installed. Why did the gauge jump to full ungrounded and empty grounded?

Well, howdy to Huntingtown! Smoke inside the headlights isn't good...could indicate a headlight about to die on you. I've seen this happen before and that's always what it meant for me. As for the fuel gauge, your sender may not be working. If the sender and gas tank don't have a good ground, the needle will go to full. If you ground the circuit and the needle goes to empty, it suggests your sender is not doing what it should. The sender registers resistance...that's all it does. Measures the resistance between the gauge and ground. 0 ohms resistance is going to give you an empty reading and 30 ohms resistance is going to give you a full reading. If you look up in tech tips (at the top of this section) there is a well-written tip on testing your fuel gauge/sender there.

You could also have a bent float arm on the fuel sender. Pull it out of the tank and ground it with a jumper wire, then run it though its range of motion and see if it tracks with the gauge. I ran out of gas once, so I bent the arm to show empty when I had a 3 gallons still in the tank as a back up. I don't mind that it reads full a lot longer then it should, it's way better then walking!

Thank you Jon G and Joe H.

Thick white smoke in a headlight is because a bit of air started getting into the bulb and the filament is burning that gas making tungsten oxide.
Bulbs can leak slowly at the pins on the back side
A bulb can be new and leak or it can be 70 yrs old and still holding tight
I never pay for old bulbs at the junk yard now because too many tested good but had filled with air and smoked and burned out quickly or sometimes instantly on me.
You may as well replace any bulb that has signs of internal fogging or smoking before they fail permanently on the road.
-s

both lights smoked?

How old are your headlamps? When they smoke you'll usually find a crack in them or condensation.

12v sealed beam Philips or Wagner Halogens are excellent. I used to prefer Sylvania but they've changed their nomenclature. I think the best ones are the cheaper of the two choices Sylvania offers. The expensive ones are those blinding blue ones that don't last as long.