J95 - 3.4 Petrol - Tacho stuck

[Jötunn]

Hi all,

I'm having a slight issue with my newly acquired LHD 1998 J95 3.4 manual.

When I turn the engine on the rev counter goes from 0 to 2500 rpm. It does not budge until the engine is turned off when it returns to 0 again. On the drive home from picking her up I decided to flick the guage.. It suddenly sprung into action and worked normally, but I haven't been able to get it to work like this again.

Does anyone have any ideas what may be wrong? Is there an earth that could directly disrupt the signal from the crank?

 

[Shayne]

I've no clue on this one my boats tacho is wired to the alternator if thats any help?

The flick fix suggests to me the wire is touching another behind the clock giving it a constant set voltage

 

[Jötunn]

I've no clue on this one my boats tacho is wired to the alternator if thats any help?

The flick fix suggests to me the wire is touching another behind the clock giving it a constant set voltage

Yeah I had thought about that, I'm a tad worried about taking the cluster apart though... hopefully it's something easy to get at!

 

[Shayne]

I removed the cluster from my 80 with some trepidation a couple of years ago and the fact i can't remember a single specific about it tells me it turned out to be very straight forward and self explanatory . I'd still try cleaning up alternator connections first , the flick might have been a fluke just because you were looking at it with curiosity that one time it came right and it happens randomly , you just don't notice because most of us have a preference for watching where we are going rather than watching clocks . Not doing the former can have fatal consequence , not doing the latter can get you fined