Wire colours to coil?

[bhpjon]

Afternoon all, i have three white with black tracer wires, and one black wire going to my (cars!!!) coil can anyone confirm if this is correct please?

[GreenV8S]

White with black tracer is conventionally switched ignition, which should go to the coil +ve. You should have a wire from the coil -ve to the ignition module. Also connected to this wire are the trigger feed to the ECU and the trigger feed to the rev counter. It doesn't make any difference to the behaviour which side these are connected to (i.e. at the ignition module end, or the coil end) but the ones I've seen have all had the ECU feed at the ignition module end - the rev counter connection seems to vary.

[spend]

Isn't the wiring schema dependent on where the ign amp was originally located (on dizzy or by coil)?

Dave

[GreenV8S]

spend said:

Isn't the wiring schema dependent on where the ign amp was originally located (on dizzy or by coil)?

Dave

The routing of the cables clearly would, but the circuit is essentially the same in either case.

[v8 racing]

On a serp you sould have 1 black + side of coil, 1 white + side of coil and 2 white/black that are coil -, the black is 12v live, the white takes it power from the black to the ign module/amp, the white/black ones are one is the trigger to the injectors and the rev counter (they are spliced together in the loom) the other is the negative from coil to the ign module/amp.

[bhpjon]

v8 racing said:

On a serp you sould have 1 black + side of coil, 1 white + side of coil and 2 white/black that are coil -, the black is 12v live, the white takes it power from the black to the ign module/amp, the white/black ones are one is the trigger to the injectors and the rev counter (they are spliced together in the loom) the other is the negative from coil to the ign module/amp.

Thanks very much for that clear description, do you know if the white/grey wire is from the alternator please as it is currently going spare after rebuild? cheers

[v8 racing]

Indeed it is.

[spend]

Is that the weird W+ supposedly for the LR tacho then?

Dave

[v8 racing]

Yes it is.

[bhpjon]

spend said:

Is that the weird W+ supposedly for the LR tacho then?

Dave

What is LR tacho please Spend? My rev counter is working even with this cable unplugged? Iam barking up wrong tree?

[spend]

AFIK, its a LR special... The rev counter is driven from the alt (it counts from one of the field coils IIRC - so same RC can be used on any engine ) then if it jumps / fails - check your drive belts & alternator. Most other cars (inc TVR) drive the rev counters from the coil,. Never understood why TVR connected the W+, it has been disconnected on mine since I first spotted it

Dave