Coil funtionality check.....diagnosis please

[Michael G.]

Good evening all. Before installing my new GM Restoration Delco 210 coil wanted to check it for function. Grabbed my Motors manual showing two different checks. With an ohm meter across the primary terminals reads 0 or closed. Secondary check from center tower grounded to case shows infinate or open. Unsure what this means as the manual failed to offer what this reading means .

Need some help from the posse. Thanks.

[Dan D.]

Re: Coil funtionality check.....diagnosis please

Should not be any resistance between the center tower and the case. Coils are configured as what is called an "auto-transformer". They are one continous winding. There is not a seperate primary and secondary. Center tower should have resistance to both of the terminals. I believe your coil is probably okay. -Dan-

[Gary S.]

Re: Coil funtionality check.....diagnosis please

This is on Dave Fiedler's web site along with other good reading:

In summary, when it comes to Transistor Ignition, there is a distinct difference between a TI coil and a coil for any other use. A TI coil can be checked and identified electrically with the use of an ohmmeter. To do this, check the resistance between the two primary terminals (positive to negative). If it's a TI coil, the results should be as follows(published resistance,at 75-degrees F):
Primary to Primary.......... 0.41-0.51 ohms

Conventional point style coils should read:
Primary to Primary.......... 1.24-1.46 ohms