Hi Jaglovers
After reassembling my engine (changed head gaskets) I found an overleft cable which
I can’t assign.
It comes from the fusebox and is white/red. I made a lot of pictures about the cables
and got some help here in the forum with the vacuum lines, cause it wasn’t complete.
But I missed this cable (see picture below).
Does anyone know where it belongs?
With that color combination, location, and what looks like a large gauge I would look at the starter relay. That is based on the wire being white/red (or seems so).
That was my thought as well…starter relay. Looks just like the starter relay wire on my Series III.
But the picture suggests it’s location is well forward near the coolant tank. The starter relay wire would be well aft of that… in the vicinity of the center of the firewall…and wouldn’t come from the fusebox
I’m stumped
Cheers
DD
I see your point so I am crawling into the stumped corner with you until better better pics come.
My guess from afar is the fog light wire, not used in all markets. My car has one like that. I had plans to use it, so far not executed. I have the lights. But, lying on my back to drill the bumper is no longer appealing.
Carl
Here I found a graph. The cable comes from the front left, where the headlight fuses and the headlight relay are (see picture below).
I’m still confused cause while i took the hood off, I removed all connections to the middle headlights which are
all in front of the car and not with this cable.
Doubt we can help the OP unless he comments on the actual color of the wire. Pic and size seem to be big gauge and white/red but perhaps he will comment.
Gregor,
I believe that is the White-Red wire for the low coolant sensor located in the coolant expansion tank on the left inner wing (fender). It senses the coolant level and illuminates the light on the instrument panel when the coolant drops below the level of the sensor.
Regards,
Paul M. Novak
1990 Series III V12 Vanden Plas
1990 XJ-S Classic Collection convertible
1987 XJ6 Vanden Plas
1984 XJ6 Vanden Plas
1969 E-Type FHC
1957 MK VIII Saloon
Ramona, CA
Gregor,
Paul is correct, that is the low coolant sensor wire although it appears to be a shielded cable. The WR wire plugs into the spade on the inboard wall of the expansion tank about halfway down, although I’m not sure why this needs a shielded wire since the ground is obtained through the coolant.
Digby
Paul you are on it. It is also a w/r wire but mine is shielded all the way to the end. Interesting that a w/r wire was used as that does not follow standards/ anyway good catch.
George,
Thanks.
I have done some extensive engine bay work in my Jaguars by myself including wall to wall clean up restorations and engine removal and replacements. The two Series III XJ6s have this White-Red wire going to the low coolant sensor in their brown plastic expansion tanks, and the two V12 equipped cars (1990 XJ-S convertible and 1990 V12 VdP) have the White-Red wires going to that sensor in the large black metal expansion tanks. I have occasionally wondered why Jaguar used White-Red wires for this sensor since some online sources for info on British Wiring say that White-Red should be “Starter switch to starter solenoid or inhibitor switch or starter relay; or ignition (start position)”. It seemed an odd choice of colors for Jaguar to use, but it is what it is.
BTW, my Series III XJ12 Parts Catalogue (RTC9886) doesn’t even show the low coolant level sensor probe (C43222) on the page with the black metal expansion tank (CAC4567) but shows it several pages earlier on the page with the radiator for some reason. I suppose that the earlier XJ12s might have had the low coolant level sensor probe located in the radiator but my two V12 equipped cars have them on their expansion tanks which seems a more appropriate place to have them located.
Regards,
Paul M. Novak
1990 Series III V12 Vanden Plas
1990 XJ-S Classic Collection convertible
1987 XJ6 Vanden Plas
1984 XJ6 Vanden Plas
1969 E-Type FHC
1957 MK VIII Saloon
Ramona, CA
Gregor,
While working on my Jaguars I have removed and replaced the small rubber bushing (C43221) that seals the low coolant level probe (C43222) in the expansion tank when I didn’t know when it was last replaced. On a few occasions the rubber was badly cracked and easily fell apart upon removal. I recommend that you remove and replace this rubber bushing while you are working in this area. It’s easy enough to do with the coolant partially drained and it would be cheap insurance ($5?) against a future coolant leak at the low coolant level probe/bushing location.
Regards,
Paul M. Novak
1990 Series III V12 Vanden Plas
1990 XJ-S Classic Collection convertible
1987 XJ6 Vanden Plas
1984 XJ6 Vanden Plas
1969 E-Type FHC
1957 MK VIII Saloon
Ramona, CA
Hi @ all
Just like @Paul_M_Novak said, it was the cable to the low coolant sensor
on the expansion tank.
I was so confused so I only searched on the top of the Engine.
With Paul Novak’s post I found the adapter.
@Paul_M_Novak I’ll also change the seal and the sensor as you recommended.
I placed a picture where the cable belongs (white/red).
Also I think it was removed while I took of the heads or cleaned up the expansion
tank cause I didn’t have a picture on my phone…
Thank you guys you really, really helped me out.
Best regards from switzerland,
Gregor
Gregor,
Thank you letting me know that my post helped you out.
If your low coolant level probe (C.43222) is working fine, there is no need to replace it with a new one. My suggestion was to replace the rubber bushing (C43221) which is less expensive (about $5 US?) and may need replacing due to age.
BTW, I removed the two cam covers of my wife’s 1990 XJ-S convertible (5.3L V12 w/ Marelli) yesterday and plan to check the valve lash and make adjustments as needed starting later today. I have adjusted the valve lash many times on my I6 cylinder Jaguars but this is a first time for a V12. I took lots of picture getting to this point, but I may need help from others like you who have done this before as I complete that work and put everything back together again.
Regards,
Paul M. Novak
1990 Series III V12 Vanden Plas
1990 XJ-S Classic Collection convertible
1987 XJ6 Vanden Plas
1984 XJ6 Vanden Plas
1969 E-Type FHC
1957 MK VIII Saloon
Ramona, CA
@Paul_M_Novak
Dear Paul
You can count on me, I’ll help you out as much as I can 
I’ll send you a message…
Yes, the rubber I found and bought already. I couldn’t find the sensor at limora.de
they didn’t list it (just like it doesn’t exist). But I’ll put an eye on it, if it doesn’t work
I’ll replace it.