A headlight "How can this be?"

I drove over to a friend's place today and drove back at dusk. Pulling into the driveway I noticed than my right headlight was out. Figured it was the bulb but I decided to check the high beams in case it was out on that side too. Turns out the low beam on that side comes on when the high beam is on.

How can this be??????:huh2:

73 Mike said:

I drove over to a friend's place today and drove back at dusk. Pulling into the driveway I noticed than my right headlight was out. Figured it was the bulb but I decided to check the high beams in case it was out on that side too. Turns out the low beam on that side comes on when the high beam is on.

How can this be??????:huh2:

Click to expand...

BECAUSE, the low beam lamp has two filaments, and the high beam has one.
The low beam filament is burned out, but when you switch to high, the high beam filament is coming on with the second aux high beam lamp.

In other words, it IS a bad lamp.

Naw Jeff, I have to disagree with you. My 'Vette "winks" as I drive, the driver side light winks on and off, it is a loose wire/bad connection, I replaced the bulb and it still happens. My high-beams all work fine.

DeeVeeEight said:

Naw Jeff, I have to disagree with you. My 'Vette "winks" as I drive, the driver side light winks on and off, it is a loose wire/bad connection, I replaced the bulb and it still happens. My high-beams all work fine.

Click to expand...

It's possible. But since he said "out", and not "flickering,", it's a tough call. I believe the Jist of the thread is the logic of how it's wired, and not necessarily what's wrong.:skeptic:

big2bird said:

DeeVeeEight said:

Naw Jeff, I have to disagree with you. My 'Vette "winks" as I drive, the driver side light winks on and off, it is a loose wire/bad connection, I replaced the bulb and it still happens. My high-beams all work fine.

Click to expand...

It's possible. But since he said "out", and not "flickering,", it's a tough call. I believe the Jist of the thread is the logic of how it's wired, and not necessarily what's wrong.:skeptic:

Click to expand...

That's correct. It was a logic question. I thought about the two filament possibility but dismissed it.

Why would they do that? Redudancy?

DeeVeeEight said:

Naw Jeff, I have to disagree with you. My 'Vette "winks" as I drive, the driver side light winks on and off, it is a loose wire/bad connection, I replaced the bulb and it still happens. My high-beams all work fine.

Click to expand...

You're gonna disagree with an electrician over light bulbs.? Bad move.

So, the low beam doesn't work but when flicking on high beams the low beam filament works and the high beam one not? If so, it's a wiring issue. If the low beam never works but the high beam does, it's the bulb but if I read your post correctly you specifically say when turning high beam on the low beam on that side works...right?

Twin_Turbo said:

So, the low beam doesn't work but when flicking on high beams the low beam filament works and the high beam one not? If so, it's a wiring issue. If the low beam never works but the high beam does, it's the bulb but if I read your post correctly you specifically say when turning high beam on the low beam on that side works...right?

Click to expand...

Correct.

Passenger side low beam light does not come on with the driver's side low beam. Switch to high beam and all four lights come on.

big2bird said:

73 Mike said:

I drove over to a friend's place today and drove back at dusk. Pulling into the driveway I noticed than my right headlight was out. Figured it was the bulb but I decided to check the high beams in case it was out on that side too. Turns out the low beam on that side comes on when the high beam is on.

How can this be??????:huh2:

Click to expand...

BECAUSE, the low beam lamp has two filaments, and the high beam has one.
The low beam filament is burned out, but when you switch to high, the high beam filament is coming on with the second aux high beam lamp.

In other words, it IS a bad lamp.

Click to expand...

Twin_Turbo said:

So, the low beam doesn't work but when flicking on high beams the low beam filament works and the high beam one not? If so, it's a wiring issue. If the low beam never works but the high beam does, it's the bulb but if I read your post correctly you specifically say when turning high beam on the low beam on that side works...right?

Click to expand...

In the low beam are 2 filaments a low beam filament and a high beam filament both have separate wires to them. Its a bad headlamp.

73 Mike said:

That's correct. It was a logic question. I thought about the two filament possibility but dismissed it.

Why would they do that? Redudancy?

Click to expand...

When the low beam LOW filament is on the light is directed lower on the road due to the way the glass is made and when the low beam HIGH filament is on the light is directed up and further down the road.

DWncchs said:

73 Mike said:

That's correct. It was a logic question. I thought about the two filament possibility but dismissed it.

Why would they do that? Redudancy?

Click to expand...

When the low beam LOW filament is on the light is directed lower on the road due to the way the glass is made and when the low beam HIGH filament is on the light is directed up and further down the road.

Click to expand...

That seems a little more reasonable.

I'm not sure why but this struck me as extremely odd.

Gee, I had the same problem and thought mine was a bad headlamp too, turns out it wasn't, does that make me wrong? I tried the high beam thing and got the same results, that's why I went and replaced the lamp.

Logic questions..... I agree! but then I disagree! I guess you are just going to have to replace the bulb and see if it fixes it or not. I'll be happy to give you the GOOD bulb I took off my car if you want.... hate to throw it away.

Did you get the headlight problem worked out ?

Damn electrickery...

DWncchs said:

Did you get the headlight problem worked out ?

Click to expand...

Inquiring minds want to know.....

73 Mike said:

I drove over to a friend's place today and drove back at dusk. Pulling into the driveway I noticed than my right headlight was out. Figured it was the bulb but I decided to check the high beams in case it was out on that side too. Turns out the low beam on that side comes on when the high beam is on.

How can this be??????:huh2:

Click to expand...

Didja get it fixed yet?