Does the speed transducer send it’s signal to the trip computer first, or the cluster first, or does it split to feed them both? Or does it loop the signal through the cluster?
Last night the speedo dropped to 0 for a little bit, then bounced back on. This happened a few times and trip computer inst. mileage dropped to 0 concurrently. Before I tear the dash open, or condemn the transducer, I want a clear understanding of where the signal actually goes.
Break out Jaguar Schematic S57. The circuitry is clear there.
I’ve got to break out my trombone for that reply. You aren’t an engineer by any chance?
The transducer feeds both the trip computer and the speedo in parallel, Paetersen…
Your symptoms indicates a transducer fault - with no signal from the transducer the computer will likely refuse to compute anything related to speed/distance. Check connections at the transducer; they are exposed and prone to failure…?
Frank
xj6 85 Sov Europe (UK/NZ)
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Check your connections, but most probably it’s bad contacts inside the transducer.
You can pry it open and resolder the joints, it worked for me.
connections are good and clean at the transducer, I am a big fan of reflowing solder joints- I’ve saved many expensive modules and clusters that way.
I missed what MY car we’re talking about. On the XJ-S, earlier models had a transducer on the tranny, but later it was replaced with a pickup on the diff sensing steps in the ring gear carrier. If the XJ went the same route, and if this car has the later style diff pickup, note that there’s a “black box” that conditions the signal from the diff pickup before sending it on to the speedo, trip computer, cruise control, etc. – and the black box fails far more often than the pickup itself.
Nice music…
N0.
Carl
Also that the transducer is firmly attached, Paetersen - and, of course, a bad connection may be elsewhere. You could take the transducer out and test it with a drill and voltmeter - not for precision, but to ensure a ‘constant’ output…?
Frank
xj6 85 Sov Europe (UK/NZ)
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Kirby,
The OP did not provide a year or model of the car he is asking about. I believe that it is a Series III XJ6 and not an XJ-S. So it should have the transducer on the BW66 transmission.
Paul
There was a time that the odometer was 'adjusted" to reflect less vehicle mileage. The advent of the reversing drill allowed that. l
Climb under. Undo the speedo cable at the transmission. chuck it into the drill. Reverse rotate for a spell. Watch the miles go away…
No, I never tried it. No real concern as to the mileage… Just pleased if my old critters ran and drove and looked decent…
Carl
On every odometer I’ve ever fiddled with, turning the cable backwards would run the odometer forwards. A mile in reverse gear still adds a mile to the car.
Or merely disconnect the drive and watch the tach for speed control. call
Over a decade or so my son bought a nice 95 Ram Cummins powered 4x 4. lottsa miles. bu, not all. some unrecorded. Friend sold it a very good price. It remains in service, Worked hard at times, Tow duty. 400k now. Moved his machine shop a few times!!!
Carl
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The pros use quicker methods, Carl…
Frank
xj6 85 Sov Europe (UK/NZ)
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