As others have stated, Pontiac ran only the resistor wire- no ballast. However, these Mallory seem to want the ballast, also. If you do have the ballast, what voltage are you seeing at the coil + when the key is on, engine not running, then with it running? If it's 9v or more, then something's wrong. I think if it's more than 6v with these Mallory, it's still too high, but don't quote me on that yet, as I also will check to verify soon, unless someone with knowledge of these would care to chime in. Yes, it does seem like maybe you have a possible bad ground somewhere. I would check them all. Check for bad/shorted wiring also. You might want to check your voltage regulator & alternator, if you haven't done so already. A bad ballast resistor can cause all sorts of nasty things to happen. (These symptoms included, maybe not so much the headlight thing, though, but possible). You can take an ohm reading on the ballast (with wires disconnected) and compare it with Mallory specs for your unit (get the module #). I just haven't made that a priority yet on my list.