Rev counter ?????

[Mr Soft]

Very occasionally while driving, the rev counter goes haywire. Then settles back down. The engine (JX) note does not change. It has happened on motorways & twisty A roads, on the flat & on hills.
Anyone experienced this or have any ideas?

Rob

[ninja.turtle007]

Very occasionally while driving, the rev counter goes haywire. Then settles back down. The engine (JX) note does not change. It has happened on motorways & twisty A roads, on the flat & on hills.
Anyone experienced this or have any ideas?

Rob

Sounds like a loose connection. When it happens reach under dash, right hand side of steering wheel and give the connector block a wiggle. This helps on mine.

[Mr Soft]

Will give it a try, thought it may be something like that, but also thought it may have been the over glove box light as this keeps falling out, but have insulated the cables terminals, connectors to prevent contact with the metalwork below the dash.
Thanks Ninja!

[AngeloEvs]

'Haywire'?
Do you mean that the RPM indication drops and then returns to normal intermittently or that the indicated RPM increases and reduces intermittently at a steady throttle? As a general observation - Diesel Tachos rely on a good alternator output signal (from the W Terminal) and I would check that first, the condition of the Edge connector and finally the mebrane pcb that pushes onto the rear of the Tacho. Diesel tacho's can be tested for function and RPM calibration but require appropriate test equipment.

[Mr Soft]

Angelo, the needle goes from high end revs to low end revs (or vice versa) very occassionally then settles back to rest @ whatever it was at (acceleration/decceleration depending), usually 3000 - 3500 rpm on the motorway. Dodgy connection it could be. Engine revs sound is constant.

Rob

[AngeloEvs]

Do the simple things first and check connections at Alternator and at dash board. Remove the edge connector from under the dash and check that the Copper strips on the flexible membrane panel are not oxidised or tarnished. Always worth giving them a clean with a dab of Brasso and soft cloth to buff them up. Remove the Dash cover and feel for the membrane connection at the rear of the tacho - with engine running apply some light pressure and obserev the tacho needle, repeat with the edge connector refitted. If all fails its 'out with the dash' or checking the Alternator itself.