Help!

What is the Primary, what is the secondary parts of a coil?

With an ohm meter how do I measure the primary and the secondary parts of an ignition coil?

What is the correct readings on the ohm meter for a coil that is to be use with points ignition?

What is the correct readings from the ohm meter for a coil to be used with electronic ignition?

These are some of the readings from a ohm meter on two different coils I have.

Coil (#1) that reads between the pos. and neg. terminals 1.7 ohms, then from the center post to either the pos. or neg. terminals it reads 7.76 with the volt meter set to read ohms.

Coil (#2) that reads between the pos. and neg. terminals 2.5 ohms, then from the center post to either the pos. or neg. terminals it reads 9.35 with the volt meter set to read ohms.

Thanks
Bill S

Bill,

Sounds like you are on the right path. The primary winding or "coil" is across the positive terminal and the negative treminal. The secondary winding is across the positive terminal and the coil wire post. The ohm range on a standard non-resisted coil is 1 to 1.5 ohm across the primary winding, and about 10 to 20 thousand ohm across the secondary winding. Your meter probably has a K before the ohm shape, meaning about 9000 ohm which is OK. The 2.5 ohm on the second coil across the primary winding may mean an internally resisted coil meaning that you don't have to use a ballast resistor, I am not sure on that one I dont have one to test for specs.

Bill,

Sounds like you are on the right path. The primary winding or "coil" is across the positive terminal and the negative treminal. The secondary winding is across the positive terminal and the coil wire post. The ohm range on a standard non-resisted coil is 1 to 1.5 ohm across the primary winding, and about 10 to 20 thousand ohm across the secondary winding. Your meter probably has a K before the ohm shape, meaning about 9000 ohm which is OK. The 2.5 ohm on the second coil across the primary winding may mean an internally resisted coil meaning that you don't have to use a ballast resistor, I am not sure on that one I dont have one to test for specs. One other thing, I don't think there is a differance between coils for electronic or points they are both externally regulated with the ballast resistor on the firewall and probably carry the same part number at the parts store. That coil #1 does not sound to skookum.

When dealing with low ohms, short the leads together so you know the resistance of the leads (not all ohmmeters can be zeroed out). Then subtract that from your reading.


And I agree, it's probably Kohms for the second reading.


Here's the specs for stock 64 points coil:

Automatic
Primary: 1.4 - 1.55 ohms
Secondary: 9200 - 10600 ohms

Manual
Primay: 1.65 - 1.79
Secondary: 9400 - 11700

Both
Ballast: 0.5 - 0.6 ohms

_________________
Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes