New ballast for F96T12HO produces flashing, no steady light

I have old school T12 lights in my garage. The dual-bulb fixtures are mounted into my ceiling. After many years the very old ballasts are all starting to die so I decided to buy 4 new ballasts and replace them all.

The replacement ballasts clearly state they are for F96T12HO lamps, and the wiring diagram completely matches the diagram for the old ballasts (white/black for power, 2 reds to 2 red wires, 2 blues to 2 blue wires, 2 yellows to 2 yellow wires. I feel like I have the right ballast and the right wiring.

So I rewire it exactly the same but the light doesn’t work! Arggh! It flashes every few seconds for 3 or 4 times, then does nothing. I feel like this flash is some kind of internal signal about what it perceives as the problem, but I can’t google up anything to help me figure it out.

Anybody know about these things?

It’s an odd test, but do the tubes stay lit if you hold your hand near them? If so you might check whether the new ballasts are well grounded to the metal frame of the light holder.

And, are you sure you have “High output” fluorescent tubes installed?

I think that you’d have to change the tubes at the same time, if you had old type tubes along with old type ballasts.

Ballast labeling is odd — I’ve seen brand new recent but old type magnetic coil ballasts labeled “solid state ballast” — technically true, it’s iron and copper, both of them are solids.
But that’s not the same as an “electronic ballast”

Yes, I am SURE the new ballasts are grounded to the frame. I have a sheetmetal screw holding one end of the ballast into the fixture and I see bare metal where the head of the screw contacts the ballast. It then contacts the fixture by nature of the threads.

Oh yes, definitely 110W HO cold weather tubes. I also tries some ES 95W tubes too - same thing.

Mine are new ballasts, not rapid start but ‘Programmable’ start which (I think) just means they pause a moment before lighting the lamps. Not rapid start. Either way the bulbs should work. I tried 2 differnt sets of bulbs (the 110W ones and then the 95W ones).

These are the new ballasts.

either the bulbs are bad or you got a bad batch of ballasts.i would watch ebay for NOS magnetic units.send those things back!

Turns out I had a bad receptacle (where the pins of the bulb go in) - a pin was mangled and either shorting or not passing juice properly