Which coil do I need

[rpgrainger]

My 1975 1850 auto has been converted to electronic ignition...been off the road since 2017...went to go and get it started but I must of borrowed the coil for another car....do I need a ballested one or non ballested one
Many thanks
Rob

[yorkshire_spam]

Not sure about a '75 but on my '73 1850 it's ballasted and the ballast resistor is obvious. (Not like the sodding Spitfire where the resistor is a "special" wire in the loom!)
The ballast can be seen here (high wattage ceramic "potted" resistor) https://forum.triumphdolomite.co.uk/vie ... 95#p306716

[Bumpa]

With most electronic ignition sets I have come across you need a full 12v supply, cutting the ballast resistor out of circuit. For a 12v coil you need one that measures about 3 ohm across the connectors with all leads disconnected. A coil for ballasted ignition measures about 1.5 ohm.

[soe8m]

With most electronic ignition sets I have come across you need a full 12v supply, cutting the ballast resistor out of circuit. For a 12v coil you need one that measures about 3 ohm across the connectors with all leads disconnected. A coil for ballasted ignition measures about 1.5 ohm.

And with the inline or in harness resistor of 1,5 Ohm the total resistance is 3 Ohm again... So you can choose.

Jeroen