Townsville Speedo Help Needed

[Smackhawk]

Hi guys, my speedo on my 300Tdi has packed it in, bounces and stops... now only works 1% of the time. Happy with the transducer fix, but I want to make sure this is what it is before I spend the $$$.

...it could be the transducer or wiring between transfer case and dash...

if anyone in Townsville could help me with my speedo transducer diagnosis by lending me theirs for 15 mins... it'd be a great help.

[stock]

Sorry smackhawk 300tdi what.............disco?? if you pop it out and put a drill on it it will help, I've ran disco for 10yrs + and never had a transducer fail but have had earth and wiring trouble.....................

[Smackhawk]

It's an auto disco 300TDi, tried the drill etc, but that still doesn't tell me if the signal output from transducer is faulty, or if the wiring needs replacing...

...so if I put a transducer on that I knew worked, and (using drill or driving) got a steady speedo needle, I'd know it was my transducer at fault. If the problem persisted... I guess wires need replacing, and I'd save getting a new transducer.

Am I thinking correct?

[pistolpete]

have you gone through a puddle of water recently?

let me find a thread I posted about the same problem...

http://www.aulro.com/afvb/discovery-1/136427-speedo-problem.html

the part worked a treat

[Smackhawk]

Yeah I read it... and hoped it was as simple as just cleaning it out... I just don't trust it's the transducer... could be the wires downstream.. and for ~$60-150, I'd rather know for sure.

Thanks though... yours is good now then Pistolpete?

[pistolpete]

perfect sine the change.. its a pain in the ass to change though, very fiddly to get too... but not difficult..

[Blknight.aus]

you can also use the digital output signal from a decent digital mulitmeter to test them...

remove the connection from the tranducer, clip on the probes and look for a steady speedo indication. if it doesnt work the first time, reverse the probes and go again.

[Smackhawk]

you can also use the digital output signal from a decent digital mulitmeter to test them...

remove the connection from the tranducer, clip on the probes and look for a steady speedo indication. if it doesnt work the first time, reverse the probes and go again.

so... put multimeter onto output of transducer and spin with a drill to test?
...what voltage am I looking for?

...or are you saying I should pump some amps down the wires instead... but once again... what voltage are we talking?

I should also mention that although my Tdi has 300k on it... the transducer itself was new in 2008... some 30,000km ago. That's why I'm leaning towards it being the wiring... I may just bite the bullet and take it to an auto sparkie!

[Blknight.aus]

a good meter will have a digital output signal. feed that onto the harness side and observe the speedo.

[Smackhawk]

Yep, it was crappy wiring after all. Transducer was fine, but the wiring that went above the transmission was cactus..... new wire, 2 days on... all good :)