S1 speed sensor trouble?.

[Stu160]

Hi All

My speedo stopped working earlier this year, and i had just presumed it was a broken cable again, but checked it out tonight, and it seems its not. I have 5 v at the connector when powered up, but still no spedo. Anyone had any problems with the speed sensor itself?..

Cheers

Stu

[BiggestNizzy]

Never the sensor, the wiring is,always ropey.

/no help

[hiscot]

Never the sensor, the wiring is,always ropey.

/no help

yep i would cut and replace the wiring first , a lot further back near the main harness .
it could be as you move the wire to check for voltage you are connecting the break ,
fit new pins to the socket whilst you rewire
at least it will solve the wire problem once and for all ( they rot along its length )

[sendmyusername]

My mates speedo/stack failed. Not the easiest or cheapest to get a hold of to test.
Not sure how the stack works, but if it needs a non-pulsed voltage, can't you borrow a power supply and connect it to stack to test before splicing and dicing your wiring ?

[robin]

It requires a train of pulses with zero crossing to make it work (i.e. the pulses should be positive and negative).

Tut has just such a thing that he can no doubt make available to Stu should he require it for testing purposes ...

Cheers,
Robin

[tut]

No probs, just had my annual use of it.

tut

[2F45T4U]

my road speed sensor was measuring open circuit so fitted a new one and it now works perfectly.

before fitting it i took the time to measure the resistance of the new one for future fault finding.

new sensor= 620Ω

voltage at sensor measured at disconnected plug= 4.96v (5v)



this might help someone.

[mwmackenzie]

Keeps the mileage sweet does that lol, check the speed on your GPS

[Rag_It]

Speedo has stopped working on mine today as well. Rev counter working fine, nothing from the Speedo, except one very quick blip of it shooting up then nothing!???

[robin]

Sudden failure is most likely a wiring break. If you have the skillz to use a multimeter, then split the loom plug in the wheel arch (you might have to remove road wheel - cannot remember), ignition on, measure the voltage across the two terminals on the car side - should be +5V (or -5V depending on which way you attach the probes). Now turn the multimeter to measuring resistance and measure the resistance across the wires leading to the wheel speed sensor. Should be somewhere in the 100-1000 ohm range (given the above 620ohm). If it's very low (like <100 ohm) or very high (meter reads >1000 or 0L) then the sensor is likely bust.

Cheers,
Robin

[Rag_It]

Robin.... I thought you knew better than that!! I have little skillz and even less when it comes to mechanical ones! Always happy to learn under supervision but I'll live with it until it can be dropped off at it's second home MMC as getting the front clam done!

Good to know it's probably just a sensor and not a whole new stack!

Thanks.

Dave