guys,

im doing a little checking around before i try to fire up my new motor.

when i have the key on, both the + and - sides of the coil (an msd type 2 or 3 .. cant remember) get about 12 Volts in reference to ground. and when i have the key off, there is about 1 ohm between them.


does this sound right to you? id rather find out now than when i try to fire up the car...

thanks

One ohm seems low to me, but may not be wrong. Is your meter calibrated? Not that I'm one to talk, my Fluke was cal'ed last in 1989...

You may want to disconnect one side before ohming out it and don't touch the contact points with your fingers, not that you are anywhere near 1 ohm.

I think a points coil is grounded on one side, but I can't say for HEI or aftermarket like MSD. Try measuring the resistance to ground with the key off from both sides of the coil.

Resistance isn't too meaningful here, since the ignition isn't a DC system. Sort of anyway... Its a pulsating DC system using AC principals to generate high voltage ;/

You have to isolate any circuit before taking resistance readings. To get a proper reading you must disconnect the coil from the circuit.

A points coil grounds through the points, when they open the coil discharges the stored energy to the spark plug.

An HEI in-cap coil typically has about 1/2 ohm of primary resistance. Point-style coils may have a bit more. Overall, I'd expect ~1 ohm to be in the ballpark.

Secondary resistance is a 'whole 'nother matter.