T5s come on for 3 seconds then off

[mike31154]

Give us more info on the fixture, dual lamp, more? Many dual lamp configurations running on a single ballast will do this if one of the lamps is weak or on the way out. It's the EOL or 'end of life' safety feature of many of the newer T5 ballasts. The ballast will sense one of the lamps is at the end of its life and turn both off after a couple of seconds.

Try a new set of lamps before you get too concerned over a possible problem with the ballast. It's an easy way to narrow down the problem.

[High tide]

Sounds like your ballast is shot.

[BlueWorldAquatic]

More than likely the ballast. Could be the bulb too, did you try other bulbs?

Possibility of it being a solder connection or ground too

[bryceschutte]

Long story short i got my end caps wet and they did the same thing. I waited till the where dry and it fired right up.

[martinmcnally]

It seems like they got wet and I think some salt got in there. I remove the bulbs put them back in and it works fine. However it happens everyday now. Tried cleaning everything out of the end caps but its a nuisance now. Everyday I have to remove the bulbs and put them back in to get it to work.

Its a Tek light fixture 36" x4

[RuGlu6]

happens sometimes to T5's most likely loose wiring.

[BlueWorldAquatic]

Originally Posted by martinmcnally

It seems like they got wet and I think some salt got in there. I remove the bulbs put them back in and it works fine. However it happens everyday now. Tried cleaning everything out of the end caps but its a nuisance now. Everyday I have to remove the bulbs and put them back in to get it to work.

Its a Tek light fixture 36" x4

Get some electronic contact cleaner from canadian tire. Spray liberally and should solve you problem. Or you can just replace the endcaps.

Ken

[The Grizz]

Does your light have an acrylic cover on it to keep moisture out?