Rev counter not working

[smithymc]

With the coupe finally running, I noticed today that the rev counter is dead.

This is hardly a priority and it may be as simple as corrosion on connections,  but any clues on where to start when I get around to it?

Thanks.

Mark

[MattNoVAT]

Pop the instrument binnacle out and check the circuits, the plastic fatigues and the copper circuitry breaks.  That's where I'd start, if the circuits are broken then start looking for a replacement binnacle as the plastic circuitry is difficult to repair.

[lanciamad]

Not sure about carb models, but on my IE it's ran off of the coil, so I'd check for corrosion and trace the wire from coil as far as you can for any damage, then look at what Matt's said, could well be a trapped wire, bad connection or circuit break.

[capriblu]

What age car have you got ?

I've just replaced/overhauled the ignition on my car - 2l carburettor with Bosch electronic ignition.   On my car the feed to the rev-counter runs from the negative terminal of the coil  (i.e. the one furthest from front of car) its a green and black striped wire.   I needed to establish this as I replaced the original Bosch black ignition control box and needed to find the correct wire to provide the signal to the rev-counter.

Check the connection at the negative post of the coil.  If you have the Bosch electronic ignition you might be able to part unravel the wires feeding from the negative post of the coil, identify and separate the green/black striped wire and trace continuity back from coil to instrument binnacle.

[MattNoVAT]

This is a S1 1600 if I recall correctly.  The chocolate brown with green interior.

[smithymc]

You've got it Matt -its 1976/77 -Tradtional coil and bosch distributor with points.

Matt

[capriblu]

You've got it Matt -its 1976/77 -Tradtional coil and bosch distributor with points.

Matt

I've just looked at a few wiring diagrams for earlier cars and they also show a direct green/black wire feed to the rev counter from the negative terminal of the coil.

[smithymc]

That wiring colouring seems to check out on my car, so a good point to start. The binnacle seems a favorite though if the printed circuits are anything like the tail-light interiors.

Thanks for all of the advice as ever.

Mark