1986 XJ6 Speedometer Issue
 

I understand that my 1986 XJ6 has an electronic speedometer. The speed needle is stuck somewhere around 25MPH (doesn't go up or down, just forever stuck). The odometer is working and the trip meter is also working. Additionally, I believe the average speed is working on the onboard computer. Does this sound like my speed sensor mounted to the transmission is ok? In that case, I assume that the actual speedometer gauge must be bad and that I need to replace the gauge. Does that sound correct?

Yes, if the odometer is working, the tranny speed sensor is fine.

Before I replaced the speedometer, I would try to fee up the needle by moving it by hand (some dis-assembly required!)

Hi,
I am helping my landlord fix his speedo issue on a Sept. '86 build date XJ6, and all of the pictures I've seen online look different than what I'm seeing.
I checked the rear passenger side of the transmission, and there looks to be a two wire sensor held in by two ~13mm bolts in front of the driveshaft U joint area above the transmission cross-brace.
Am I looking at the transducer or is it located somewhere else? Potentially on the differential?
Thanks,
John
John

You might have a Series III XJ6 or an "XJ40" type XJ6. Very different cars; both built simultaneously for a period of time. This explains:


https://www.jaguarforums.com/forum/x...i-have-213579/


If you have a Series III XJ6, the speedometer transducer is on the RH side of the transmission case, more aft than forward. Here's a pic

https://cimg5.ibsrv.net/gimg/www.jag...b239c8bfc9.jpg



If you have the later "XJ40" type XJ6, I'm no help, sorry, but the guys in the "XJ40" will be glad to assist

Cheers
DD

Does anyone know the correct assignment of the pins on this connector?

Logic tells me that the yellow/black wire should be 12V as that will be shrouded on the car loom connector, therefore the brown is signal (you would think)

My beloved S57 tells me that yellow is signal and green is 12V (and neither of these colours appear on my car or the new transducer)

I am asking as my car has modified wiring as it had some weird arse Taiwanese transducer in there, so I am starting from scratch.

Think I have been able to find an answer. There are a couple of references related to speedometer problem determination that say to look on the yellow signal wire on the transducer when spinning it and looking for a square wave output. So it seems that yellow/trace is signal and brown is battery.