How do you determine if you have a bad coil? What are tell tale signs?

The Haynes manual states that they can be tested as follows , “Using an ohmmeter, check the resistance of the coil. Do this by touching the probes of the ohmmeter to both the positive and negative terminals of the coils. Check each separately. The primary resistance should be 1.35 plus or minus 10% ohms for both coils.”

Thanks,

 

That's how I checked my old coils.

Not sure about the exact resistance off the top of my head, but I used the haynes manual specs as well. (I tested my set when everything was working fine) and was within that spec.

 

But how do you tell if you have a bad coil? Are there tell tale signs?

 

I have always checked at night by taking one wire off and pulling it away about an inch and having someone crank the engine, If it looks strong your good but if it looks like there is very little spark going threw go get a new one, Repeat on second coil when done just make sure to plug the wire back into the first one before you do it.