Odd Flourscent Lighting issue

[pentavolvo]

Ok here we go. I have 4 flourscent fixtures in my garage all on same circuit/switch. Been installed 2.5 years. 2 of them were older fixtures from way back then and 2 of them were brand new fixtures. Last year one of the old ones took a dump so I replaced it with a new one so I had 1 real old fixture, and 3 newer ones.

Well last few weeks the older one wasn't always turning on but if i twisted the bulbs around i could get it to fire up. I did try changing both bulbs out no issue. Just the other day it stopped working all together so I went to homedepot and got a new fixture. I had old one down and unhooked and all of a sudden one of the other fixtures starts flickering and doing odd things. So I install the new light and its flickering and doing weird things (it worked fine when I tested it before I put it up). Now all 4 of my lights start doing odd things flickering but it seems to be only 1 of the 2 bulbs in each fixture. If I turn switch off and then back on they all start doing crazy things but will calm down and all will work right or maybe all but one.

I am loosing my mind over this, I went back and checked a bunch of connections and I have good voltage hot to neutral and hot to ground.

Any ideas would be greatly appreciated, I am ready to burn the garage down.

They are all 4 foot fixtures with T12 bulbs

 

[Charles (in GA)]

Really should be buying T8 at this point in time.

Check the grounds, Make sure that each fixture has a ground, and the ground is continuous to the panel, no loose connections, no paint under the wire at the ground in the fixture (scrap the paint off around the screw) make sure everything is good and tight.

I didn't believe it, but picked up a fluorescent troubleshooting sheet at Home Depot (a tear off on the edge of the shelf) one of the first things it said to do was make good grounds to all fixtures. I was trying to get a couple of lights in the back room of the place my GF worked, to come on. They had changed the bulbs to no avail. I had taken the bulbs in and out two or three times. Finally took the grounds apart, scraped off all the paint around them, re connected everything tight and reinstalled the bulbs, and presto it works.

Not sure what the deal is, and lots of fluorescent fixtures have operated for years without any ground at all, but this was like item #1 on the list on the sheet and it did fix the problem for me.

Charles

 

[ambenz]

I am guessing one of the fixtures is feeding back "noise" through it's ballast via the 120V connections and causing the others to change their output.
Try disconnecting one at a time until the problem goes away, then plug in the others.
It also could be some other appliance connected to the circuit recently...just a suggestion...
...I like checking ground, good suggestion Charles!

 

[pentavolvo]

I am guessing one of the fixtures is feeding back "noise" through it's ballast via the 120V connections and causing the others to change their output.
Try disconnecting one at a time until the problem goes away, then plug in the others.
It also could be some other appliance connected to the circuit recently...just a suggestion...
...I like checking ground, good suggestion Charles!

i think you are onto something with the backfeeding thing. i am starting to wonder if origional fixture is even bad. the junction box at one of the lights is where power comes in and then it splits out from there and each fixture gets a homerun. i checked ground in that junction box and it was good. crazy thing they all work fine now hours later i guess time will tell but they are all cheaper fixtures maybe its a sign to dump them all.

i know i should be running t8 but i had all t12s alreayd and didnt want an odd ball

 

[eljefino]

I like the "noise" idea. When I plug in my dumb battery charger (just a simple noisy transformer) my T12s go nuts for a few seconds until the battery charger "settles in".

 

[kbs2244]

I would agree with the idea of checking the grounds inside the fixture.
All of them, including the ballast mounting.
I believe the newer ballasts are more sensitive to grounding.

 

[pentavolvo]

Crazy but now they all work fine