Removing the rev counter

[MikeM]

The tacho is playing up, and looking at the forum this seems to be a common problem. The needle either doesn’t move at all or if it does it reads high. I want to get the instrument cluster out to investigate but I’m getting stuck. I can follow the instructions in the manual but when it comes to pulling the cluster out upwards through the binnacle there doesn’t appear to be enough wiggle room to manoeuvre it. Before I break anything is there a trick to removing it? Everything is disconnected and I can move it around under the binnacle opening but there doesn’t appear to be enough clearance to pull it out. The two large screw fittings that hold the dashboard and dash cover in place seem to be most in the way but those aren’t moveable. Any suggestions?

Thanks, Mike

[dapinky]

You may find it easier to separate the front part (perspex and surround) from the main part....... it is a bit fiddly (especially when having to put it together later!) but it helps get it out. Other than that, it is just a case of rotating and twisting it around to find the route out...... it does come out that way when the orientation is correct.

[MikeM]

You may find it easier to separate the front part (perspex and surround) from the main part....... it is a bit fiddly (especially when having to put it together later!) but it helps get it out. Other than that, it is just a case of rotating and twisting it around to find the route out...... it does come out that way when the orientation is correct.

I did wonder about trying to separate it in-situ, but was concerned about brittle plastics breaking. I might try that when I have another go. Otherwise I guess I will try reorienting it as much as I can. Alternatively I’ll leave it until I next pull the facia off again to replace the old alarm.

Thanks, Mike

[MikeM]

So I still can't get the gauge cluster out through the top binnacle. The aftermarket alarm module is too close to it under the dash, and is preventing it from being manipulated sufficiently.
So in the meantime I'm trying to diagnose the problem with the rev counter in-situ. The rev counter either doesn't register at all, or if it does it only moves the needle between about 4000 to 5000rpm. The position is dependent upon the engine speed, so at idle it sits at just below 4000rpm and then when I rev the engine it goes upwards but only to about 5000rpm.
I've tried checking the inputs, it's getting 12V and it's also getting the signal from the coil pack, which shows 32Hz at idle, which seems to equate to 950rpm, and it increases with frequency linearly with engine speed. If the signals all look good then I suspect it must be the rev counter itself at fault - sound reasonable?

Tacho_Signal_Small.jpg

[Saltire]

Sorry to have to tell you, Mike: I had the same problem, and only managed to get mine out by removing the steering wheel (I have a Nardi wheel). On the first occasion, I removed the whole wheel including the boss; second time around I removed the wheel and spokes from the boss using Allen keys, and still managed to get the binnacle out.

[Tuga2112]

this comes from a point of ignorance. (i dont know the electronics in the rev counter_) and an educated guess (because this is a fairly common issue with 25+ year old electronics)
but i have a sneaky suspicion your rev counter electronics will have a capacitor leaking/failure

removing the whole thing is the only way to visually inspect.

unfortunately for you.. i have removed that cluster not long ago... and done a video on a repair of the rev counter.. and i cant recall how i removed it. and didnt film that part... and the electronics that i repaired were not related to your problem.