Technical Rev counter a bit flaky

[madrat]

Hi, got a bit of a strange problem with the rev counter on My Marea (105 JTD 1999) The other day I noticed it wasn't working, but as soon as the engine got warm it sprang into life again, since then it dose the same every time, starting from cold its dead but as soon as the temp gauge gets to quarter it springs back to life and works perfectly until the next time. Can anyone suggest what the cause could be???

 

[madrat]

Where is the sensor that feeds the rev counter ?

Why dose it work when the temp gauge get to just over the quarter mark then stops working as it gets to half way then comes back again?????

Its a 1999 105 JTD

 

[EI4GGB]

most likely to be a faulty cluster. the rev counter signal comes from the ECU, so its not a sensor problem as such. if you have the equipment (multimeter with frequency counter, a scope or even an led would do), check the rpm signal at the cluster connector (look at relevant wiring diagram to get pinouts). if its always present, the cluster is most likely faulty.

 

[madrat]

OK thanks, I have tried banging the cluster and top of the dash when its not working but still nothing so don't think its as simple as a lose connection, will have to have a bit of a play when the weather isn't as wet and cold.