florescent fixture problem

bernie963

I have a 20 " single tube fixture which is about 28 years old in a clothes closet. The tube most of the time does not light unless the switch is turned on and off several times. I replaced the tube and no change. last week I bought a new fixture and bulb, replacing both. same result. today I replaced the switch, same result. If I wiggle the tube, sometime it lights. the ends of the tube glow when it does not light. any thoughts out there.

I did test the old switch and it seems fine. it was back stabbed and the replacement I used the screw terminals. I am wondering if there is a junction box with a bad connection buried somewhere. bad tombstones maybe???

bernie

joed

Is there a ground connection? Some fluorescent fixtures will not light with the ground missing.

Your old fixture could needed a new starter.

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ionized

Bad ground
bad connection between ballast and luminaire metal

bernie963

thanks, I still have the old fixture, I will wire a cord to it and see if it works. I will check out the ground. both the old and the new were(are) connected to the ground wire. could be a loose ground connection in the wall switch box. will investigate that also. I know this no light situation has been going on a long time. the adjacent closet has its switch in the same box with no problem, so it could be a ground issue in the plastic switch box.

again thanks,

bernie

AltaSparky

did you buy the right fixture? you likely need a 120V ballast if you are in north america.

If the new fixture was installed correctly you could have a problem with the wiring. Measure the voltage across the two wires that you attracted the fixture to. You should get somewhere around 120VAC.

Looking at your old fixture, make sure the connections at the tombstones are in good condition and that the ballast is wired correctly. There is usually a diagram on the ballast.

bernie963

hey, Just pulled the switch out of the wall. found one ground wire not under the wire nut!!! It was wrapped around the bundle of grounds but not under the wire nut. I pulled it apart and reconnected the pig tail grounds. put everything back together, turned on the power and still the same problem.

there are two switches in the box, one for each closet. one lamp has always worked and the other has this no light problem. the ground that was wrapped but not wirenutted appeared to go to the affected lamp. I did not test with my ohm meter to confirm.

symptoms again, bulb (tube) not lighting, glowing at one end. touch bulb and it lights. if you flick the switch on and off several times it will light without touching bulb.

I have replaced the fixture, the bulb, and the switch. I have checked the ground and have jumped from the switch to the fixture with a separate ground wire so the fixture is double grounded. I rechecked all connections and tightened the ballast mounting screw. the cover, behind the bulb, has been on and off so many times the paint is scrapped off so I know that bond is good.

where do I go from here? any suggestions???

ionized

Two luminaires, old and new, each with new lamps. and neither works? Neither works when wired directly to a cord and plugged in?

I hate to write it, since you seem to be able to figure things out, but are you getting the lamps into the sockets correctly? It seems like you have worked through the ground question adequately. The only thing I have left is that your old unit had a bad ballast (or starter) and the new one is bad out of the box.

bernie963

just wired the old unit to a cord and it worked every time i plugged it in. Hmmmm. next is to do the same with the new unit (when the wife is not home as it is in her closet). if it works, there must be a wiring problem between the switch and the fixture, but what?

will have to test each wire (black, white and ground ) again.

could be that the non wire nutted ground was the problem with the old fixture and there is a bad ballast "out of the box" in the new fixture!! go figure. details tomorrow (i hope).

and yes the bulbs were (are) installed correctly. i agree with "look at the simple things first" approach. sometimes the simplest of things are missed first time around!!!

thanks,

bernie

ionized

You keep your wife in her closet?

bernie963

all is well, wife is out of the closet and the light now works. evidently the non wirenuted ground was the original problem. tested the old fixture and it was good. I disconnected the new fixture and wired the old lamp fixture into the original house circuit and it worked. re-installed the old fixture and we are good to go. tested the new fixture, no good (out of the box). go figure.

good example of why just twisting grounds with out a wirenut is no good. originally it always worked, then on occasion it would work intermittantly (as the copper tarnished a little) only took 28 years from the new construction to now to find the problem!!!

bernie963