NOS Headlight problem diagnosis

[James F.]

I bought a pair of NOS Power Beams. After installation in the car, one immediately fogged up and the other turned black at the inside top of the bulb. The seller warranted them and wanted them mailed back for examination. He is claiming, after examination by an ASE tech, that the problem lies with my car. He says bad wiring or faulty headlight switch. Would it be possible to ascertain the car as the problem just from the examination of the bulbs? I currently have bulbs in the car that work, both NOS and new halogens. I am aware that the seals on the back of these old bulbs are prone to deteriorate from age. Could the tech be correct or is it impossible for him to determine??

[Jay G.]

Re: NOS Headlight problem diagnosis

It sounds like the vacuum in the bulb was lost and the filament burned up when you turned it on. This is one of the rationals that Lectric Limited gives for purchasing their reproduction bulbs rather than NOS bulbs as they have seen a lot of NOS bulbs go up in smoke as soon as they are powered on.

I don't see how the car or wiring would have any affect unless there was substantially more than 12V applied to the bulb.

Jay

[Norm C.]

Re: NOS Headlight problem diagnosis

James... totally agree with the two previoius posts..... The challenge is if yours is a 72, like mine is, then you know we live with the "one year only" bulbs used on Vette's I believe Camaros, so the suggestion from Lectric Limited doesn't apply as they don't reproduce the 72's Yes on 71's and earlier and I believe 73's, but not enough demand for the 72's.

I've bought several, and had the same thing with a few. (We're talking about 37 yr old light bulbs.... surprised any seller still warrants them to begin with) When most sellers "warrant" them, they check them out with a continuity meter because they're afraid of the same result. This of course doesn't have the full 12 volts nor does the bulb come up to temp. The only variable that I've not encountered is mixing old technology with the Halogens. Don't know if that could cause higher resistence.

If you're into having your car judged, suggest you save NOS or OEM used for show only. If I were to guess, I'm betting the seller needs to honor the warranty if he warranted them.

[Jeff G.]

Re: NOS Headlight problem diagnosis

He is claiming, after examination by an ASE tech, that the problem lies with my car. He says bad wiring or faulty headlight switch.

I'm amazed that someone would claim such a thing, especially claiming a tech diagnosed it to your car. The only way to fry the bulb filaments would be to hook them up to a much higher power source than the car could possibly provide, OR, no vacuum in the bulb.

[Joe C.]

Re: NOS Headlight problem diagnosis

I bought a pair of NOS Power Beams. After installation in the car, one immediately fogged up and the other turned black at the inside top of the bulb. The seller warranted them and wanted them mailed back for examination. He is claiming, after examination by an ASE tech, that the problem lies with my car. He says bad wiring or faulty headlight switch. Would it be possible to ascertain the car as the problem just from the examination of the bulbs? I currently have bulbs in the car that work, both NOS and new halogens. I am aware that the seals on the back of these old bulbs are prone to deteriorate from age. Could the tech be correct or is it impossible for him to determine??

James,

Compromised electrode seals-no vacuum. Chances are the seller knows it, and judging by what he said to you, good luck getting your money back. Never, ever buy an old sealed beam without testing it before paying for it. And, even if you do this, is no guarantee that the beam is not on its way out. Inspect the electrode seals for disintegration. The reflector should have NO traces of blackness near the top, and there should be NO milkiness near the top, either. If any of these telltales exist, then test the beam first, and only buy it if you never intend to energize it.

Joe

[Harmon C.]

Re: NOS Headlight problem diagnosis

This post has questions . power beams are 73 and later no repops. 72's are the small T-3's on the bottom no repops. All old bulbs may burn out at any time. Buy them at swap meets with a 12 volt test seeing them light up. Most bulbs that are old are discolored and only NOS look great and they may smoke and burn. I quit mailing bulbs years ago as their are too many problems. I sell bulbs at Carlisle once a year lite them up and give you a ten foot money back deal. If you reach the next vendor their yours because if you drop them most of the time their going to smoke. I broke a case of 12 NOS small t-3's and they all smoked and burned.

[Jack H.]

Re: NOS Headlight problem diagnosis

There are two issues here: (1) oxygenation (white 'smoke') and (2) Edison effect (blackening of the glass at the top). The first results from leak(s) in the globe allowing oxygen and moisture inside. Even when brand new, these lamps may have exhibited a VERY small/minor amount of 'smoke' when first powered up due to stray amounts of oxygen & moisture left from an 'imperfect' evacuation of the lamp. However, that level of 'smoke' is SO MINOR you might see no trace...

The Edison effect (stray electrons 'boiling' off the filament and rising to the top of the lamp) results in the glass darkening. This effect is typically VERY slow/gradual over time. But, it can be accelerated by an over-voltage situation.

As others have said, I doubt your car's electrical system caused this because the alternator just isn't capable of APPRECIABLY raising the battery voltage that much...