Only one bulb works in 4 ft fluorescent light?

[Denwad]

I have two four foot flourescent light fixtures. In both of them only one bulb works.

The bulb is ok. If i switch the bulbs in the fixtures, same result.

Now if i take the cover off, there is only one ballast. Is it possible for the ballast to go half bad?

 

[Josey Wales]

Are you saying that you put the two lit bulbs in the same fixture, and only one lit up?

 

[RECox286]

How old are the tubes ? How black are the tube ends ?

If you swapped the working tubes into the same fixture

do both light, and if you try them in fixture #2 do they

both light ? Same question for the non-working tubes,

except do they not work in both fixtures ? I would try

4 fresh tubes.

Uncle Bob

 

[rockwithjason]

Check the tombstones for loose or disconnected wires. Those little push in connectors sometimes give the wires up

 

[zmaxmotorsports]

Check the tombstones for loose or disconnected wires. Those little push in connectors sometimes give the wires up

Any time you change one bulb in a fixture change all the bulbs in the fixture,Bulbs are cheaper than ballasts.
When you start seeing any part of a bulb turning dark change the bulbs.
Another thing to check is to make sure the bulb holders/tombstones are not pushed part way out of the mounting brackets.
If the ballast feels really hot or is ******* oil out of it,its time to chuck it.

 

[Denwad]

Are you saying that you put the two lit bulbs in the same fixture, and only one lit up?

yes

How old are the tubes ? How black are the tube ends ?

If you swapped the working tubes into the same fixture

do both light, and if you try them in fixture #2 do they

both light ? Same question for the non-working tubes,

except do they not work in both fixtures ? I would try

4 fresh tubes.

Uncle Bob

The tubes have no blackness in them at all, they all work. Just one set of tombstones doesn't work on each fixture.

Check the tombstones for loose or disconnected wires. Those little push in connectors sometimes give the wires up

I noticed these detach from the frame, i didn't realize the wires came out

duh how else are you supposed to change the ballast.

I'll have a look at this.

Its very dark in the garage, and these are t12 fixtures, not very bright. Maybe I'll spring for some T8HO or maybe even T5s :O

 

[Josey Wales]

I feel your pain, I'm struggling with FOUR fixtures that don't like to turn on when it's under 50 degrees.
Might check out those LED conversion bulbs,,,

 

[cajunfirehawk]

I HATE 4ft fluorescent fixtures! I have 1 in my laundry room that has given me fits for 6 years, swapped the entire light fixture out and the new one does the same **** as the OP states, ONE tube! Plus two in my garage and two in our kitchen, they will be coming out and going to LED fixtures this year. Laundry room and garage will be soon maybe tomorrow!!!

 

[cybrdyke]

I have two four foot flourescent light fixtures. In both of them only one bulb works.

The bulb is ok. If i switch the bulbs in the fixtures, same result.

Now if i take the cover off, there is only one ballast. Is it possible for the ballast to go half bad?

Den,
Since these are T12, I'll give you these thoughts....
There are many different kinds of T12 ballasts. Most of them are 2 lamp rapid start magnetic ballasts. These ballasts have the lamps wired in series, which is a circular circuit. This means that it's nearly impossible for one lamp to come on full brightness and the other to be out, because the dead lamp would break the circle.
Cheap "shoplights" used a different kind of ballast. You would often find that they would use 2 choke ballasts. These are smaller, cheaper, and less efficient than the other types. The key word in that sentence was "cheaper". Typical shoplights will have a choke ballast in each end of the fixture, each running one lamp. If one of them went bad, it would explain your situation.
If you have a 2 lamp magnetic ballast, there are a few connections you should check. Obviously, check the connections at the sockets at each end of the dead lamp. One end will be yellow wires, and the other end will be either red or blue wires.
The yellow wires are common to all the lamps and they jump from socket to socket to socket. You should check ALL of the yellow wire connections. You also need to check the connections at socket adjacent to the dead lamp sockets. This adjacent socket "feeds" your dead lamp sockets, so the bad connection could be there. If your dead lamp sockets have a red wire, find the nearest adjacent red wire socket and check it. If your dead lamp sockets have a blue wire, then check the nearest adjacent blue wire socket.
Good luck.
CD

 

[nadogail]

Cybrdyke,

That has to be one of the best lessons written on fluorescent lighting, thank you for sharing.

 

[FTG-05]

I HATE 4ft fluorescent fixtures! I have 1 in my laundry room that has given me fits for 6 years, swapped the entire light fixture out and the new one does the same **** as the OP states, ONE tube! Plus two in my garage and two in our kitchen, they will be coming out and going to LED fixtures this year. Laundry room and garage will be soon maybe tomorrow!!!

Keep the fixtures, just bypass the ballast and replace the tubes with LEDs:

http://www.beeslighting.com/product-p/t818w1200bixxdf40f1.htm

I used two of these bulbs to replace the four T5 fluorescent bulbs in my kitchen. I'll never buy flor bulbs ever again. Once they start to go, I'll bypass the ballasts and replace the bulbs with LED bulbs.

LED bulbs are instant on and come on full power even when cold.

Good luck!.

 

[Richard Cranium]

My lights have a fuse on each line

 

[Denwad]

Here is a picture of the fixtures as they are. I haven't really dug into it yet, but i'm about to pull one off the ceiling and putting it on the bench and digging into it.

and as you can tell in the pictures, both lights have the exact same problem.

 

[jhelrey]

Anytime a known good bulb or many don't light, replace the ballast. Home Depot has them for cheap. Electricians always want to voltage test but as a building engineer, if it works one day and nothing the next is always the ballast

 

[Denwad]

it looks like these are some cheap-*** lights anyway, lowes has whole t-12 fixtures for 12$ or i can get the ballast for 16$, no brainer right?

 

[CNGsaves]

^ ^ Don't waste money buying "new dinosaur" T12 light fixtures. You can get T12 fixtures by truckload off of CL from businesses yanking them out.

If you're staying with flourescent lights then go with T8 if you have shorter ceiling, and T5HO if you have taller ceilings.

 

[zmaxmotorsports]

Anytime a known good bulb or many don't light, replace the ballast. Home Depot has them for cheap. Electricians always want to voltage test but as a building engineer, if it works one day and nothing the next is always the ballast

 

[cybrdyke]

Here is a picture of the fixtures as they are. I haven't really dug into it yet, but i'm about to pull one off the ceiling and putting it on the bench and digging into it.

and as you can tell in the pictures, both lights have the exact same problem.

There's no label on the ballast??
The wiring in this fixture appears to be very abnormal. My guess is that it's wired incorrectly, but without the ballast label, it's not possible to be sure.

I agree with others about troubleshooting it. By the time you figure out what's wrong with it, you could run out to the big box store and have new T8 fixtures installed in their place.

Good luck,
CD

 

[MarkG]

Keep the fixtures, just bypass the ballast and replace the tubes with LEDs:

http://www.beeslighting.com/product-p/t818w1200bixxdf40f1.htm

I used two of these bulbs to replace the four T5 fluorescent bulbs in my kitchen. I'll never buy flor bulbs ever again. Once they start to go, I'll bypass the ballasts and replace the bulbs with LED bulbs.

LED bulbs are instant on and come on full power even when cold.

Good luck!.

If you ever have that fixture down, I'd be interested in seeing pics of how you did that! I'm tired enough of replacing my 4' bulbs that I'm ready to tear into something like that too!

 

[nadogail]

There have been times in my life that I have been guilty of spending $$$ worth of time and material in an attempt to save $, or try to prove that I am smarter.
We should allow the OP the freedom to try to do I things his own way.

Experience is the name I give my mistakes; I have lots of experience.

 

[Denwad]

There's no label on the ballast??
The wiring in this fixture appears to be very abnormal. My guess is that it's wired incorrectly, but without the ballast label, it's not possible to be sure.

I agree with others about troubleshooting it. By the time you figure out what's wrong with it, you could run out to the big box store and have new T8 fixtures installed in their place.

Good luck,
CD

I'll get a picture of the label soon enough.

I have alot of time but not enough money so troubleshooting the fixture to me is an adventure in economics and education!

 

[jhelrey]

After seeing the pics on my computer vs the phone. Buy new ends also and rewire the completely or you will confuse yourself. Just follow the diagram on the 2 bulb T8 ballast. Easy!

 

[Denwad]

Here are some additional pictures

unfortunately I think I will have to repair these fixtures, as they were installed with those drywall anchors that expand and tighten up to the drywall. I suppose i could remove them and replace with new ones, but i'm having trouble because right now the screw just keeps spinning might have to cut the threaded part to get these lights off without ripping a bunch of drywall off.

 

[FTG-05]

If you ever have that fixture down, I'd be interested in seeing pics of how you did that! I'm tired enough of replacing my 4' bulbs that I'm ready to tear into something like that too!

Never took it down. I rewired it as it was, connected to the ceiling. All I did was rewire so one side was hot and the other side was dead since that's the way the LEDs were.

Longer version: Bypass the ballast by unhooking it from the black/white wires coming from the switch. Reconnect them to the two wires from one tombstone on one end of the fixture. Disconnect the other end tombstone. Repeat for the other set of tombstones (I only did two tombstones, I left the other two sets set up for florescent lights even though I don't use them).

It wasn't hard at all.

 

[cybrdyke]

I'm still going with mis-wired. But the ballast is missing the label, so I cant tell you how to fix it.
Where I see a problem is in two places...
One end has a white jumper from socket to socket. From what I can see, the other end has no such jumper. This is a problem.
Also, I see blue and red in the same socket. Normally, this would be incorrect.
CD

 

[SALIV8]

As others have said the label appears to be missing. If I were to guess I would rewire the fixture this way:

On the ballast end with the date code, Each of the 2 wires (red and either blue or yellow) would fire up one bulb each. The red wire would be on one end of the lamp holder and the blue or yellow of the same pair would connect to the opposite lamp holder of same bulb.

 

[FordTruckWench]

I'm still going with mis-wired.

To which wires is the incoming 120VAC connected?

 

[Denwad]

I'm still going with mis-wired. But the ballast is missing the label, so I cant tell you how to fix it.
Where I see a problem is in two places...
One end has a white jumper from socket to socket. From what I can see, the other end has no such jumper. This is a problem.
Also, I see blue and red in the same socket. Normally, this would be incorrect.
CD

i agree, i've looked at magnetic/electronic wiring diagrams online and NONE of them look like this.

 

[cybrdyke]

To which wires is the incoming 120VAC connected?

Hard to tell, but it looks like the incoming black is connected to black and the incoming white is connected directly to the lamps, which is unusual, but not unheard of.
You can see the white wire going to the socket and then jumping to the next socket in one of the pictures....and there's no white wire on the ballast.
CD

 

[Norcal]

Those fixtures were cheap junk even before they came out of the box, get some decent ones & be done with it.

 

[NUTTSGT]

Cheap T12 fixtures. I had the same issue so I swapped my out for T8 8' 4 bulb fixtures. I started replacing so many of those T12 bulbs at one time, I was dating the bulbs to try to figure out what the heck was going on and how long they were lasting.

 

[rburke65]

Have you tried a new lamp?.......really people!? READ!

 

[Denwad]

Have you tried a new lamp?.......really people!? READ!

well, i thought i said in my original post that I tried both bulbs in both places and both bulbs light in one socket, but not in the other...

 

[cybrdyke]

The bulb is ok. If i switch the bulbs in the fixtures, same result.

Have you tried a new lamp?.......really people!? READ!

 

[ExxWhy]

Have you tried a new lamp?.......really people!? READ!

Ha! I got it.

 

[rburke65]

I'm thinking you are the only one ExxWhy! TYJ!

 

[Denwad]

Alright the fix is in.

I purchased 2 T8 ballasts, 8 new lamp holders and 4 T8 bulbs and wired it all up according to the label on the ballast

works great , had to drill a new hole for the new ballasts because they were much longer than the old ones

much brighter in the garage now !

 

[chico0511]

couldn't you just get a t-8 ballast for your old light with t-8 bulbs and be done with the t-12 lights?????

 

[Norcal]

couldn't you just get a t-8 ballast for your old light with t-8 bulbs and be done with the t-12 lights?????

They are trash fixtures so not worth the effort.

 

[Denwad]

couldn't you just get a t-8 ballast for your old light with t-8 bulbs and be done with the t-12 lights?????

that is exactly what i did

They are trash fixtures so not worth the effort.

this is true , but due to the fact the fixtures are wierdly attached to the ceiling, I opted to replace the ballasts with T8 ballasts and bulbs

it was also fun and interesting to do it