Coil loom wiring conundrum 1989 CTi

[lagonda 41]

To clarify, my CTi has the "normal" coil bolted to the NS inner wing, not the later inlet manifold mounted item.

 

Changing the clutch, I decided to dismount the wiring to the coil, ignition amplifier etc to make things less cluttered for the job. This revealed a rather odd junction ... a red wire diectly connected to a green wire, the joint covered with insulating tape, so presumably this is a repair? made after manufacture. Seems rather odd to connect red directly to green, especially given these two colours are, respectively, positive and negative at the coil.

 

Hopefully my photos will clarify ... the first shows the join, and the second shows the wires in situ before disconnecting.

 

So ... should these two wires be connected together?!

[Tom Fenton 1,526]

If it ain't broke don't fix it.

[lagonda 41]

Normally I'd agree, but here it looks like something may have been "broke" before my ownership and "fixed" wrongly! My CTi remains "broke" as I continue to have trouble with it cutting out, especially when hot, as in stop start traffic. I remain convinced this is an electrical issue, given resistance (and thus poor connection) increase with heat.

 

I've since discovered that amongst my spares I have a piece of the coil loom including coil , amplifier and distributor connectors. It's clear from that that two red wires go to coil positive. Mine has one red, one green! That green wire can be seen dead centre in my second photo, and runs alongside the green-to-red wire in question.

 

This pair of green wires run, in sleeving, to a black relay mounted on the front of the NS suspension turret; Lucas (so it isn't a factory item) SRB520 ... 21989507. A red wire also goes to this relay, this can be seen entering the sleeving at the bottom of the same photo. This red wire feeds from a thick brown wire in corrugated sleeving running from the headlight area backwards and down into the scuttle (to the fusebox probably).

 

Prior to my ownership (since 2003), the car had an alarm and or/immobiliser fitted, and I know these were notorious for inducing electrical issues and poor quality connections. Could this be part of that system? Alternatively, could the relay be providing some useful purpose? I'm tempted to remove the relay and its wiring, revert the red-to-green wire to simply red to coil positive, remove the red wire picking up from the thick brown one and properly rejoin the brown wire if it proves to have been cut for connecting the red wire and joined poorly. One concern is that the red wire currently connected to green may have been alternatively connected elsewhere ... is that likely?!

[SRDT 150]

Not all cars with carbs had an electric fuel pump so old alarms worked mainly by cutting the ignition.

It could also be for a kill switch, it's not as simple as cutting the pump but if you don't have the right wiring diagram it's tempting to work on the better know ignition.