J

johnboytech

New Member

• Jul 16, 2010

• #1

Hi. my 96 Disco 2.5 tdi speedo has packed up, it was dodgy previously but only when going 60+ for more than 20 miles or so, then it fixed itself! it must be magic. Don't know much about landies as bikes are more my thing. neither the needle moves or the mileage works, having had a quick look underneath im presuming it has a electric sensor rather than a cable. anyone got any idiot proof tips/directions/ suggestions of where to start and what to look for?

 

discool

Well-Known Member

• Jul 16, 2010

• #2

That's right you have a road speed sensor (transducer) mounted on the side of transfer box first check the electrical plug and the single fixing bolt is tight.

 

Last edited: Jul 16, 2010

J

johnboytech

New Member

• Jul 16, 2010

• #3

Hiya. This is the stage I got to. All is tight and ive cleaned the crap off the contacts on the plug and made sure no loose connections. Next?

 

discool

Well-Known Member

• Jul 17, 2010

• #4

Assuming every thing is working in the speedo pod warning lights etc therefore the fuse No.14 has not blown then "next" would to replace the transducer it's not unknown for them to go faulty, unfortunatly theres no way of testing them.

 

WolfyDave

New Member

• Jul 17, 2010

• #5

Hi there,
You can test the transducer using a meter set to OHMs....

Remove the transducer, put your meter leads on the transducer,1 on each terminal,then spin the drive wheel on the back using a rechargable drill with a cut down pencil with a rubber/eraser fitted to the end. If there is no change in the resistance when the transducer is spinning,its FUBAR'd i'm afraid.

Hope this helps
Dave

 

discool

Well-Known Member

• Jul 17, 2010

• #6

As it is a transducer it provides a/c voltage when turned, the voltage maybe pulsed as with some Rover cars and the votage is low may be around 0.5vac, it appears that the stats. for a discos tranducer are not available (well i can't find them) therefore if you don't have this info you won't know if any multimeter readings, voltage, current and resistance given are correct.

 

J

johnboytech

New Member

• Jul 17, 2010

• #7

hows the best and easiest way to remove the transducer? On my back from underneath? or I think I may have read somewhere there may be an access panel under the rear seat?

 

discool

Well-Known Member

• Jul 17, 2010

• #8

Yes underneath if i'm correct you can see it, or you can see and get to the allen bolt but it was a few yesrs ago when I looked