Timing Light Q

[pmpski_1]

OK, this can't be that hard -

I went to set my timing today and the light wouldn't fire. The light is a 10 dollar cheapie from Harbor Freight and has been banged up since I used it so I decided to head off to Sears to get a new light. Back in the garage, the new light won't fire either.

I tried a couple different wires, and I checked the voltage on the timing light clamps while the engine was running - 14.9. I even tried to use both lights on another car. Neither light would fire. I know the HF one worked in the past cause I used it for timing my motorcycle.

What am I missing? I find it hard to believe that a light that worked before and a brand new light are both broken.

If it matters, I just upgraded to HEI and a rebuilt QJet. Truck runs, but it's a bit rough.

Thanks