So you don't know if any of the GP were really bad. What made you think any were bad?

Here is a test that requires no electrical equipment: Remove the GP from the engine. Grip the GP with a locking plier (Visegrip) in the hex area. Touch the end of the GP where the wire attaches to one terminal of the battery and the opposite end of the locking plier to the other battery terminal. The tip of the GP should glow red hot in less than 10 seconds.

If the GP glows red hot, it is good. If not it is no good. Its that simple. I hope you didn't throw away your old GP. By the above test you can find out if they are still good.

NOTE: This test only applies to the newer pin type, parallel, 12 volt plugs and not to the older loop type, series, 1.2 volt plugs.