Intermittent Rev counter ?

[Mohawk 620]

Hi All, has anyone had an intermittent Rev counter. To explain that it’s more on or off at startup. Some days when I start it & set off Rev counter does not work. Other times it’s fine. On the days it does not work immediately it starts working after a few miles !   I suspect a wiring fault. 

 

Any wisdom or ideas ? 

 

Thanks

 

mohawk

[Grum 661]

Hi Mohawk.

The first thing I would do is unplug the connector at the back of the instrument panel and give this connector a squirt of WD-40 or CRC 2-26 or similar and re-try.

 

You may also have cracked joints on the pins to the printed circuit board Tacho connections. (not sure how the Tacho is physically connected to the PCB or main plug as I've never had a 5th gen.)

 

You could also try the voltage checks as suggested in the service manual for the Tacho.

 

Is the problem mechanical/vibration induced?  Can you give the Instrument Panel a bit of a knock and the Tacho begins to work or stops working? This would definitely locate the fault to the Tacho or its PCB and connector, rather than wiring further away.

 

Good Luck.

Cheers.

[KevCarver 541]

It's been a couple years since I had my gauges apart, but I believe the screws that hold it in place also make the connections to the printed circuit ribbon thing.

[Mohawk 620]

Thanks Guys,  I thought I'd ask before I strip the fairings off to access the instrument cluster. Yes it could be any of those, will try to get some time in next week or so to check it.