Hello, I discovered a mystery wire on my 72 XJ6, US LHD model. The wire is disconnected and taped and I really can’t see a likely home for it.
The wire is a heavier gauge, cloth covered with black plastic shielding. The color code looks to be dark red with either white or yellow stripe (it’s a little faded). The wire branches off the large bundle that exits the firewall by the battery. It was routed under a clip in front of the battery and then hanging loose down into the engine bay. There is a push on connector which would fit a spade terminal.
I thought at first it connect to the horn, but appears too short without re-routing. Any thoughts on this? I really can’t tell anything not functioning, other than that the car only has a single aftermarket horn.
I have a similar wire on my 73, and I once figured out what it was for. But meanwhile I aged into the memory-free zone. Here’s a guess. There is an anti-run on circuit in the later S1 cars that included a second oil pressure switch plumbed into one of the gallery plugs opposite the first couple of mains on the intake side. That switch closed, not opened, when OP was present. The anti-run on valve was wired through that switch to a special contact on the ignition switch that was hot with ignition off, not on. If your mystery wire is not for fog lights (fog wires are also visible under the dash pad) it might be the power source for the valve. If so, it is hot with ignition off and zero volts with ignition on.
Thanks for the suggestions. I will check for current as Robert suggests. The colors sound right for fogs, but it seems a little short. Perhaps the fog lamps came with a fairly long pig tail.
Red/yellow is standard fog lamp wire colours, George…
…the cars were prewired for fog lamps, as George says, but wires were usually terminated and taped at the front, for easy connection to the lamps when installed. In this case, the end you have may be the one meant to connect to the light switch - or some hidden connector. Is the spade a male or a female? A disconnected female would be powered with power switched on, but a naked spade would be unpowered…
To verify that it is ‘fog’; check for two wires with the same colours near the front bumper area…?
Frank it is but 2 points–he says his are faded and many times the wire appears orange–he obviously does not have a wire chart and the size of the wire suggests heavy current. So what do you think it is to help him?
Frank it is but 2 points--he says his are faded and many times the wire appears orange--he obviously does not have a wire chart and the size of the wire suggests heavy current. So what do you think it is to help him?
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The heavy current may imply fog lights, George – rather than some sensors, which draws little current...
Wiring diagrams are sort of useless for physical tracing unless the wire colours can be read – and as you rightfully comment, fading is certainly a problem after this long time. Jaguar was very consistent in the use of wire colours; same colours were used throughout for the same items – colours added when new items were added.
So *’dark; red/yellow* was used throughout for fog lamps as they were introduced as an option – prewired, though not that often fitted ex factory. If the wire colours found do not match the diagrams, in this case fogs, it’s a different circuit – and we cannot exclude that. Or that these wires have been added by a PO for some reason or another...
One possible explanation for the the location of this wire end, near the bulkhead, is that it has been pulled out from the separate fog light switch on the dash. This switch may or may not be in place ex factory, but as far as I recall, room was left for such a manual switch – with wiring in place. Explaining the rather thick wire, as it would be dimensioned to carry current to both fogs...
As suggested; the actual fog wires should be in place near the bumpers - to be located for final identification. Whether the search is worth while depends on if he wants fogs – or just plain, legitimized inquisitiveness as to mystery wires...which may or may not be fog wires...
Frank
xj6 85 Sov Europe (UK/NZ)
