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Which coil do I need
Posted: Mon Apr 17, 2023 12:41 pm
by 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
Re: Which coil do I need
Posted: Mon Apr 17, 2023 2:39 pm
by 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
Re: Which coil do I need
Posted: Mon Apr 17, 2023 3:04 pm
by 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.
Re: Which coil do I need
Posted: Mon Apr 17, 2023 4:52 pm
by soe8m
Bumpa wrote:
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