Incandescent garage bulb turns off immediately after being turned on

[Timur Tabi]

I have a light fixture in my garage, and when I put a normal incandescent light bulb in it, I cannot reliable turn the light on. That is, when I flick the switch to "on", I can see the bulb turn on for a fraction of a second and then turn off, and stay off. If I repeat this process a few times, the light will eventually stay on for a few seconds, but then turn off again.

The fixture does not have a light sensor in it, and it was working reliably for years until recently. Can anyone give me a clue as to what's going on?

[RBM]

Could be a bad switch, possibly a bad lamp socket

[jeff_wisnia]

1. At the risk of insulting you, have you tried a different bulb with similar results? If not, you know what to try next.
2. See if the center contact inside the socket is mashed flat so it can't make firm contact with the tip of the bulb base. If so, Turn off power and pry that center contact up with a L-bend on end on a piece of wire....straightened paperclip works well for that.
3. Does the bulb flick on if you give the socket a swat? If so, there may be a "loose disconnection" where the feed wires attach to the socket. Turn power off, drop the socket and see/fix.
4. The switch itself may be bad or one of the wires connected to it may be loose, particularly if it's a back stabbed connection. Solutions are to replace the switch or change to the screw connects.

Let us know what you find.

Jeff

[Twayne]

IMO switch or wires to the switch; unlikely switch vibratons could affect the light fixture, which is apparently what's happening.

HTH,

Twayne`

[jeff_wisnia]

1. At the risk of insulting you, have you tried a different bulb with similar results? If not, you know what to try next.
2. See if the center contact inside the socket is mashed flat so it can't make firm contact with the tip of the bulb base. If so, Turn off power and pry that center contact up with a L-bend on end on a piece of wire....straightened paperclip works well for that.
3. Does the bulb flick on if you give the socket a swat? If so, there may be a "loose disconnection" where the feed wires attach to the socket. Turn power off, drop the socket and see/fix.
4. The switch itself may be bad or one of the wires connected to it may be loose, particularly if it's a back stabbed connection. Solutions are to replace the switch or change to the screw connects.

Let us know what you find.

Jeff

[jeff_wisnia]

1. At the risk of insulting you, have you tried a different bulb with similar results? If not, you know what to try next.

1. See if the center contact inside the socket is mashed flat so it can't make firm contact with the tip of the bulb base. If so, Turn off power and pry that center contact up with a L-bend on end on a piece of wire....straightened paperclip works well for that.

2. Does the bulb flick on if you give the socket a swat? If so, there may be a "loose disconnection" where the feed wires attach to the socket. Turn power off, drop the socket and see/fix.

1. The switch itself may be bad or one of the wires connected to it may be loose, particularly if it's a back stabbed connection. Solutions are to replace the switch or change to the screw connects.

Let us know what you find.

Jeff

Jeffry Wisnia (W1BSV + Brass Rat '57 EE) The speed of light is 1.8*10e12 furlongs per fortnight.

Timur Tabi wrote:

[h]

Is there anyone, anywhere still using incandescents? Try a cfl and let us know if the problem is still happening.

[Gordon Shumway]

It could be the switch, the connection(s) at the switch, the wires from the switch to the fixture, the connection(s) at the fixture, the fixture itself or the bulb.

Doesn't anyone have any troubleshooting skills anymore?

[DD_BobK]

Agreed, also a loose connection somewhere.

Switch is easier to check but I had a bad lamp socket that gave intermittent function, dining room over the table fixture...... a real job to change out based on the fixture design.

cheers Bob

[Gary H]

[e-mail]...

Can you use CFLs in your oven and freezer?

[h]

Umm, your oven and freezer have lights? Weird.

[Ed Pawlowski]

"h" wrote

Why wouldn't they? Makes it easier to see what is going on in the oven and what you have in the freezer. My top freezer does not have one, but the side by side and the regular freezer have lights.

[HeyBub]

You said "when I put _A_ normal incandescent..." Did you mean "when I put _THE_ normal incandescent..."

If you're trying the SAME bulb over and over, the problem is a broken filament. When cold, the two broken ends touch allowing truth to the statement "let there be light". Almost instantly the filament heats up and the broken ends separate causing darkness to fall upon the land.

If, however, the symptom persists when DIFFERENT bulbs are tried, the answer is equally simple: the circuit is cursed.

[hrhofmann]

Not Wierd at all. Both my stove/oven and my freezer have light bulbs in them that go on and off when the doors are opened and closed. It really does help to see what you are doing in both places.

[The Daring Dufas]

The heat from the oven would roast the electronics of the CFL. In a refrigerator or walk-in cooler, the cold temps keep the light dim at the start because it must warm up for full brightness. The CFL lamps that work best in cold weather are the cold cathode bulbs that use the same technology as the lights behind most LCD computer and TV monitors.

TDD

[willshak]

What would have been better is "when I put _ANY_ incandescent..."

[Tony]

I don't think I've ever had an oven without a light. My current one is controlled by a switch up with the other controls. My current refrigerator only has one light on the fridge part, none in the freezer but my previous side by side one had lights on both sides. I've also never had a clothes dryer without a light, although I have seen a few that didn't have them.

[Bob Villa]

"Most" likely the switch. If this is a 3-way...even more likely (more connections-additional contacts).

[Timur Tabi]

The problem started some time after I switched to a CFL bulb. I thought maybe the bulb just didn't like the garage environment. So I tried two incandescent bulbs, and they also exhibited the problem.

[Timur Tabi]

Well, I was hoping for a technical description of the problem. If I just replaced the broken part, I wouldn't understand what the root cause was.

Anyway, thanks to everyone for your ideas -- the problem was the switch. Specifically, a worn out contact. The reason the bulb flashed before turning off is because the impact of flipping the switch was enough to cause a temporary contact inside the switch. Slowly flipping the switch would do nothing, and pushing really hard on the switch causes it to stay on (but then turn off when I stop pushing).