weak coil?

Hey Guys, My mechanic said my coil is really weak and he's surprised it even starts the engine. I'm thinking of switching over to a Mallory Unilite with vacuum advance and matching coil so figure the stock coil will have to work for now. I was wondering how do I know it's really the coil and not the ballast resistor or something? I'm not even sure if my 66 has a ballast resistor anyway and where would it be if I did?

I had a Mallory Unilite in my Mustang and thought it was really trick and easy to adjust for top performance and figure why change brands.

Get a multimeter and check the resistance across the + and - you should be able to find the stock specs in a repair manual. Or go to an auto parts store ask to see there coil for your car. Check the resistance against your coil.

Thanks Unfairlane!

If its pretty old, it wouldn't be a bad idea to replace it either way.

As Un mentioned, that has to be one of the fastest ways to check an ignition coil. When, they start to poop out, the insulation breaks down, and then provises a little bit of a short. As they get real old, the then eventially read Max. The older shorter Ford coils used to work real sparky, but I got several in the box under the bench which now give "maybe" a 1/64" spark in free air.

If in doubt, just yank a similar looking coil off another similar era vehicle, and insert the two primary wires and secondary. See if that cures things for you. Don't be picky on who manufactured it either. First you want to isolate as to if it is a coil problem, or a wiring problem. No need in going fancy if the wires going to the coil are pooped out.


Wm.