There are two T8 fluorescent tubes and an electric T8 instant start ballast. All of the lamp holders are non-shunted.

The T8 ballast has two blue wires and a red wire coming out of one side. I connect one of the ballast's blue wires to two blue wires for one of the lamp holders on the left side. I connect the ballast's other blue wire to the two red wires on that same side (using the twist-screw cover). I connect the ballast's red wire over to the opposite side of the lamps, and connect it to two yellow wires, which each connect to that opposite side's lamps. On the yellow side, there is also a small yellow wire connecting the two tubes (their lamp holders) together.

It seems to be the tube with the two red wires connecting to the ballast's blue wire where the lamp doesn't turn on.

I did read somewhere that shunted lamp holders are needed for electric instant start ballasts, so I am wondering if that is the issue. Hoping someone can help. Thanks!


  • 1
    follow the instructions that come with that ballast.
    – Jasen
    Commented Aug 23, 2023 at 15:25
  • I don't really know, but somehow that wiring diagram looks wrong.
    – crip659
    Commented Aug 23, 2023 at 15:45
  • Why not switch to longer-lasting, more-efficient LED's? Particularly for "warmer" color (lower color temp) lamps, the LED pays for itself after one or two fluorescent tube replacements. Commented Aug 23, 2023 at 16:24

1 Answer 1


You are already wiring it as shunted tombstones would be, so no worries there.

Include the other yellow wire in the red-yellow bundle. In principle it shouldn't matter but it may.

Also make sure you are using T8 tubes with T8 ballast.

  • 1
    Thanks for reassuring me about the wiring being correct. I tried replacing all the non-shunted tombstones with newer ones and I got it to work just by rotating the bulbs differently. I think the whole problem was not knowing how to rotate the bulbs in properly. Thanks for your help!
    – Joe
    Commented Aug 24, 2023 at 3:06
  • @Joe yes, that matters significantly. Commented Aug 25, 2023 at 19:24

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