Testing a Magneto Coil

[Frank, Tx]

Using an ohmmeter, the coil lead (coil to points/condenser) to ground is 1 ohm; from the contact on the coil (to rotor) to ground is an open circuit; and from the contact on the coil to the points/condenser lead is an open circuit. Is this enough data to tell if the coil is good or bad? Can the condition of the coil be determined with these measurments, or are there other measurements I can make to tell the condition of the coil ? Any help will be appreciated. Thanks, Frank,Tx

 

[teddy52food]

If the secondary winding is open , the coil is bad.

 

[PBrowning]

Hi Frank -- The coil will have two segments, one a primary winding and the other the secondary winding. The primary winding is the one connecting to the contact points and should a low number of ohms resistance - on the order of from 2 to 4 ohms. The secondary connects out to the feed into the distributing rotor and between its end and ground you should expect between 6000 and 8500 ohms.

Without getting too rough on the coil, look for a loose or broken wire -- but if indeed the secondary is open, I am afraid she is done for! (PatB)

 

[buickanddeere]

Which range is the ohm meter on while checking the coil secondary?

 

[Frank, Tx]

buickanddeere, 20k ohm range. Frank

 

[buickanddeere]

It appears you did everything right. Like the others said, time for a new coil.