Triumph TR7 Electronic ignition

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Scuttle Shaker
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Joined: 31 Aug 2015 18:49

Triumph TR7 Electronic ignition

Postby skertonman » 13 May 2018 11:21

Morning all, looking for some help/guidance before I start banging my head against the wall.

After reading previous posts regarding Accuspark electronic ignition I took the plunge and bought the kit (no 31), and a new coil to fit to my 79 TR7, the coil came as part of the package.

All seemed to be going well, as it could be after fighting with the dizzy bolts, then comes to the wiring up, and hence my call for help.

There were 2 wires to the coil low tension side, White/Yellow and White/Slate, there was a seperate White/Slate leading from the dizzy (points) to the main engine wiring loom alongside the other 2 wires going to the coil.

Anyone know how these wires and the 2 wires from the new igniter unit all connect, I've read the workshop manual, and the fitting instructions but seem none the wiser.

The previous posts mention the new Red wire goes to the ignition switch, but I can't access the photos frpm that previous post, which is some years old.

All suggestions gratefully received.


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Joined: 11 Jun 2007 22:55
Location: United Kingdom

Triumph TR7 Electronic ignition

Postby dursleyman » 13 May 2018 14:21

Need to go and check the wiring diagram but from memory the white/slate is the signal wire to the rev counter.
The white/yellow goes to the starter motor. When you operate the starter it gives a full 12 volt supply to the coil as long as the starter is engaged, instead of the usual 6 volts that it gets via the ballast in normal running.

Many electronic ignition sytems need 12 volts to operate properly so you may need to check if your new coil is a 12v or a 6v one as well.

I run my electronic ignition with a 12 volt coil so that white/yellow wire is redundant and disconnected both ends.

1981 TR7 Sprint DHC


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Location: Netherlands

Re: Electronic ignition

Postby Beans » 13 May 2018 18:02

WS goes from coil to distributor and rev counter.
WY runs from starter relay to coil and ballast wire.

The module will (probably) need a 12V feed, so best to run a wire directly from the ignition switch to the ignition.

Bypassing the ballast wire and fitting a 12V coil may have some effect on starting the engine as it will get a weaker spark.
The original set up bypasses the ballast wire during starting, giving 12V on the 6V coil. This will give a bigger spark, aiding starting.
1976 TR7 FHC (currently being restored ...)
1980 TR7 DHC (my first car, a.k.a. Kermette)
1981 TR7 FHC (Sprint engined a.k.a. 't Kreng)

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