I have an '88 Vanden Plas (XJ12) and the speedo stopped working a few weeks ago. I am trying to locate the sensor (which I have been told is on the diff) and have crawled under at every angle I can find. I have NOT be able to spot the sucker?!?!? Does anybody have a diagram/picture showing the location???

Just today the tach started acting up...intermittent not working/working/jumping. Could it be a related issue???

Thanks in advance for any advice!!

Bo...

 

The speedometer transducer on your car is on the left side of the transmission, not the differential.

(It was the mid-88 and later XJS that had the differential mounted sensor)

I can't think of any relationship to the tachometer problem...unless there a wiring or grounding problem behind the dash.

Cheers
DD

 

Thanks for the reply Doug!! The shop I use sometimes looked up the VIN number for me and told me it was on the diff??? I will look on the transmission for sure, but where would it be if it was on the diff??? This is an '88, so it may be a later one??

Thanks

 

The diff mounted speed sensors were mounted in the differential cover. If you were looking at the diff from the rear, straight on, it would be right-of-center and about half way up from the bottom.

Cars using this sytem has a finned aluminum differential cover rather than stamped stell, by the way. Very handsome.

Anyhow.....

When you're all done looking at the differntial turn your attention to the left side of the transmission. That's where you'll find the speedo transducer. Look more towards the rear of the trans. The transducer isn't AT the rear but more towards the rear than the front. It might well be partially obscured by the exhaust pipe.

You might find the the transducer wires have flopped against the exhaust pipe and melted. In that case you might wanna repair the wires first and see what happens.


Cheers
DD

 

Here's what you're looking for:

Speedometer Transducer - Parts For Series III Saloon | Jaguar Classic Parts UK


Cheers
DD

 

The differential mounted speed sensor, as used on the *XJS* cars from VIN 144262, looks like this:

Speed Sensor - Parts For XJS from (V)139052 to (V)179736 | Jaguar Classic Parts UK


Cheers
DD

 

and thank you again kind sir!!!!

Will let you know what I find....

 

Well Doug...finally got around to climbing under my Jag ( I hate it when works interrupts!!!). Finally found the sensor and the wiring is fine. I can't get to the sensor until I get the car up higher...will pull it and hopefully something will be revealed.

Stay tuned!! lol