SPEEDO JUST STOPS AND STARTS. ANY IDEAS.

[KS5000]

I have a 2001 tuscan and the speedo has started to play up in a weird way. Sometimes it works and then it just stops working, the analog and digital just drop to 0mph. When i start the car the speedo usualy works and after a while it stops working. sometimes it starts again. its very weird. has anyone had this problem, have any idea what is causing it and maybe a solution before i go to the dealership and get charged 2 hours labour for locating it. please please let me know.
Many thanks.

[Big Al.]

Sounds like the speed sensor is on it's way out, I noticed when mine started playing up when myh speedo was reading 180mph. Problem was I was in a 30 limit at the time.

[The Surveyor]

Certainly sounds like the speed sensor has got some water in it. Located on the diff and is an easy (ish) diy repair if you can get the rear of the car safely lifted.

Replacement unit costs about £80 - £100 if i can remember correctly, and available from most TVR specialists .

Paul

[tripleblack]

I had the same issue, but strangely my digital speedo keeps working well. Would that still be the speedo sensor, then?

Edited by tripleblack on Thursday 21st October 21:11

[shpub]

Having spent some time with a Tuscan owner with similar problems a couple of weeks ago... I would guess the sensor is on it's way out. The problem is that the sensor needs a 10 to 28 thou gap to work and often gets destroyed by grit or even by run out with the trigger wheel itself. Even the cars with the new upgraded sensor with a 28 thou gap have the same problem. It is a similar scenario to that of the Griffs, Chimaeras and Cerberas.

Ended up modding one of my intelligent speed sensors to work with it. The built in diagnostics and set up LEDS work so you can check the speedo is ok without the sensor or turning the rear wheels. I've now sourced the connectors so it is a simple plug in replacement.

[shpub]

tripleblack said:

I have the same issue, but strangely my digital speedo keeps working well. Would that still be the speedo sensor, then?

Unlikely but not impossible as the sensor signal is a bit strange shall we say and needs some signal processing to generate any digital pulses. It is possible that the digital side inside the dash is OK but the analogue side isn't.

[Rotaryboy]

Thanks Steve,
It was my Tuscan you fixed and both analogue and digital are all working fine now.. Cheque's in the post......

Tim

[Robertjp]

shpub said:

Having spent some time with a Tuscan owner with similar problems a couple of weeks ago... I would guess the sensor is on it's way out. The problem is that the sensor needs a 10 to 28 thou gap to work and often gets destroyed by grit or even by run out with the trigger wheel itself. Even the cars with the new upgraded sensor with a 28 thou gap have the same problem. It is a similar scenario to that of the Griffs, Chimaeras and Cerberas.

Ended up modding one of my intelligent speed sensors to work with it. The built in diagnostics and set up LEDS work so you can check the speedo is ok without the sensor or turning the rear wheels. I've now sourced the connectors so it is a simple plug in replacement.

Before i changed my LCD screen the speedo used to stick at 75 mph, have put it back together and it seems i have assembled it too tight as it has now stopped moving, i have been told there needs to be some slack in there as its a worm gear against a normal gear. If that doesnt work i will be after one of your sensors i think steve!