[Mark McLeod]

I don't remember if any of them blink. I think that on some the light just goes out, but I haven't tested them in the broken direction in a while. They get labeled and put on a shelf for later repair if necessary.

You just need a secondary way of testing them that confirms the problem before you can be sure there is a problem. That's why I suggested an old IFI controller.

They're still useful if you have a one-way device, such as, a flywheel or shooter mechanism.