Ign. coil current.

[Aussie John]

Have just put 12v across a coil and measured 15 amps, the primary resistance is 1.1 ohms [checked this against another coil] does the amplifier limit the current flow? I thought it only switched between s/c and o/c. Any thoughts guys?

[pete275]

to my knowledge the coil is ballasted, so the coil only gets about 9 volts.

I agree with you that the amp does switching only and cannot limit current. Maybe try your spare unit and measure current again? 15 amps sounds a hell of a lot to me.

[Aussie John]

Hi Pete, mine doesn't use a ballast resistor, I'm doing checks on a coil which was replaced on a friends griff which also didn't have a ballast resistor, I'm surprised by the high current but the coil on my griff measures 1.1ohms also. I would have thought maybe 5 amps would be nearer the mark, cheers, John.

[pete275]

hi John, dug up this on another post

http://www.pistonheads.com/gassing/topic.asp?t=152...

Apparently low resistance coil is needed for the demands of 8 cylinders, so 2 ohms would be correct

I run a lucas sport on mine just been and measured it 1.8 ohms across it.

[Aussie John]

Thanks Pete, you're a star, that's definitely some good info..