S2 coil connections

About 6 months ago, I loaned my engine harness to a friend restoring a Coupe. He’d lost the harness during the years-long resto. He used mine as a template.

When I got it back, the bits of tape and scribbles were not clear, and I’m stumped with the coil connections.

From the picture, there’s a single black wire, and a bundle of white with tracers on another connector.

I think I’ve got the rest in their correct places.

I have a manual with but the wiring diagram only has the FI car.

Any help is appreciated.


Firstly, Robert; do you have EI or the original mechanical points?

In the latter case; do you have the external ballast resistor assembly? And how many wires and of which colours?

Generally; plain white is power from the ignition switch - plain black is plain ground. Beyond that it gets a bit complicated - hence the need for available wire colours to possibly find the appropriate wiring diagram…:slight_smile:

xj6 85 Sov Europe (UK/NZ)

Thank you Frank,

I really appreciate your help here.

The car is a carb engine with ballast.

The 2 wire bundle are white with blue tracer, and white with black tracer.

The black wire shown comes from a condenser-shaped blue cylinder attached to the outside of the coil.

The POS terminal is to the left.

The rest of the harness is in the right place I’m pretty sure.

Thank you,


Be sure to identify coil terminal by pos and neg, as marked, Robert

And read the last paragraph first - the rest is explanatory covering a set-up that has been tampered with by a PO, or the set-cannot be positively identified…:slight_smile:

And are there any identification markings on the ballast unit, probably the ‘blue cylinder’?

Its a bit complicated; according to the wiring S2 diagram there are 3 wires connected to the distributor and 6 wires to and from the ballast unit.

Basically the ign system is very simple; a white wire from the ign key is connected to coil positive - and a black/white connects coil neg to the distributor. That’s all that is required for ignition.

However, refinements was gradually introduced - without necessarily updating the wiring diagrams to match each
car’s wiring in detail. Hence my apprehension…

To wit; an external resistor was added to protect the coil - which was bypassed while cranking, requiring wires. At the time; white/blue was powered in crank to bypass resistor. A further complication was routing tacho through the resistor unit the delivering ign power; with white/green to coil pos. In this configuration; the ballast resistor had white, white/blue green/? ‘in’. And ‘out’; white/green (to coil pos), white (dist), white/black (dist) - and a white/black from dist coil negative…

A different set-up connected the tacho directly to coil neg - simplifying the ballast resistor unit. Leaving the ballast with white and white/blue ‘in’ - and white/? ‘out’ from resistor to coil pos(!) - which looks more like your set-up? With a white/black from dist to coil neg…?

xj6 85 Sov Europe (UK/NZ)

To simplify; the purpose of a white/black, connected to coil neg from the dist, is to interrupt the coil’s ground connection to effect ignition. The white (powered with ign ‘on’) provides power to coil pos. The white/blue (powered in 'crank" only) is to bypass a resistor during cranking - to then increase coil voltage.

If the blue cannister has just one wire it’s probably a radio interference suppressor and can be ignored for now.


connect coil carefully …

problaby an uncorrect wires connection at coil and ballast …caused smoke in cap/rotor/contact !

coil top have a “+” and “-” ,use some time to brush contacts.

enjoy your start !

I got it going. The coil NEG connection was wrong.

Thank you to all who helped me out.


I have a note book in my shop. I’ve made notes and diagrams in it when confronted with and resolve connector issues… typical wire color code and relay pin number!!!

My lump has a bank of relays along the cowl. I lettered them. Starter, fans 2 fan2, etc…