Rev counter stopped working

[kevino]

Hi my rev counter sometimes on start up did not move off the zero, but when I reved the van it sprang into life, but now it has stopped completely I have had a look at the back of the rev counter and can't see a wire off , where does it go on the engine ? any clues anyone please .

[VWCamperfan]

I think it connects to the alternator which is why is doesn't respond until you rev the engine up a little. Check connections at alternator end, should be a single wire on its own with a connector in-line. Check this connector is clean and tight and the connection on the alternator itself.
I think its a blue wire IIRC.
Failing that, the alternator could have stopped charging but I would have thought the charging LED on the dash would have lit up to let you know.

[tonytech]

Rev counter works off Alternator if the engine is diesel, Coil if the engine is petrol.
T

[kevino]

Thanks for the help, and its a diesel forgot to mention that , I will have a look in the daylight .

[Syncro G]

Diesels don't work when the charge warning light is on, as you say you usally need to blip the accelerator to get that to go out. When the LED is out and the engines running you can proceed...(asuming the LED lights before startup, if not your LED circuit isn't working properly and that will prevent the altinator from energising and produicing current/W signal)

On mine the conection between the PCB and the rev counter unit itself was playing up - its a 3 pin conector. Pokeing it helps conferm its the problem. To fix it you need to use a tiny screwdriver and close up the ends of the terminals a bit that are in the black plug soldered to the PCB - remember its all obsolete and expencive so be carefull! Only the very ends of the terminals make contact with the pins on the tacho so its easy for it to work loose and loose signal. Worth doing though as my rev counter doesn't keep droping out whenever I drive across a pebble in road/white line/manhole cover/pothole/kurb/open manhole/rock/ditch/small furry animal/person once working in manhole, anymore

[kevino]

Thanks glen for taking the time to respond
Kevin.

[kevino]

Thanks it was the wire on the alternator.