Problem with flourescents

[promethean_sprk]

I have a pair of 2 bulb shoplights (that's 4 bulbs), in a kinda crude melamine boxlike hood over a 55. For some reason the front fixture usually only flickers, but will pop on once and a while. Also if I play musical bulbs, or install new bulbs it will also work - but only for a little while. The back light ALWAYS works with any of the bulbs.

At first I thought I'd cooked the ballast, so I got a new fixture and stuck a block under the hood to keep it ajar. I saw the same problem again within 10 minutes. I've swapped ballasts and bulbs, but keep running into the same issue. The other fixture has never failed to turn on for me.

The two fixtures are very close together, the inner pair of bulbs are within half an inch of eachother, might this cause some sort of EM interference? Is it bad to have 2 lights connected to the same cord/timer? Do I need a starter? What really bugs me is the back light always works. You'd think if I were cooking them that when I replaced the front one, the old one would burn up first.

In the meantime, my plants are ok with 1 shoplight all the time and one 10% of the time, but I'd like both pairs running.

I'll probably build a new hood in the next 6 months, the melamine is too heavy. (Great for aquarium stand tabletops though!)

[mbeck]

You probably have a starter problem - I have the same problem, and am replacing mine today. They look like a cylinder with 2 posts on it, and twist out.

[promethean_sprk]

These fixtures don't have starters in them. I've seen descriptions of how to install a starter in a non-starter ballast, but I got the impression from the article that this was only an issue for old fixtures. This also doesn't explain why one works and the other doesn't.

I've got a starter from the old fixture, so I'll try wiring that in and see if it helps.

[Bob Hooper]

It sounds like your reflector is not grounded. I had the same problem as you are describing, grounded the reflector and now they come on every time.
Hoop

[Godslayer]

Also make sure the bulbs are seated properly on the receptacles. I ahve had problems with flickering lights when they weren't seated properly.

[promethean_sprk]

They weren't grounded, but grounding them made no difference. I think they just insist on that so that in the event of a short you'll blow a breaker instead of a finger. ;)

I also tested all my wires, but didn't get anything. Must be it's toasting ballasts. It only seemed to be about 150' or so in there, but maybe that was enough. Maybe I should replace it with a metal halide.