Is an ignition coil, an ignition coil or do we need some sort of 'rating'. I have few random ones kicking around

I just fried mine by connecting a hot lead from the battery to it. The car ran OK but why did it overheat. Was it because the car was left idle and the points were closed?

Hence the previous question

a couple of things can do this

1. Leaving the ignition on without the engine running, if you've got points - the coil is only meant to be connected 40 - 50% of the time.

2. If it blew up when the engine was running, maybe you're using a 9v coil without a ballast resistor. If this is the case, change to a 12v coil.

HTH
David

I assume the coil you were using is was a ballasted coil, which runs at about 9volts not 12 volts

I have learnt this lesson by breaking down 4 times to and from Donnington

u will need either a ballast resister, and run a ballasted coil, or a straight thru 12 volt wiring to a "Non Ballasted coil"

clear as mud ??

regards

steve

Older coils for points ignition came either 12v or ballasted. The voltage ratting of ballasted coils varied quite between manufacturer.

ISTR Ford coils were ballasted down from the normal 13.8 running voltage down to I think 10 volts. GM coils ran at about 7.5 volts.

Modern coils tend to be custom designed for use with a specific electronic ignition system.



[Edited on 23/2/07 by britishtrident]

Ballasted coils used without the resistor will burn out points and condensors very quickly . Guess how I know!