Tachometer not working

[martfill]

Hi, the tachometer on my 1964 2.4 has never worked since I've owned it, what's the most likely cause and/or how do I test it to try to discover the fault/ cause?
Thanks in anticipation Martin

[PPV]

I would start by checking the connections and then continuity of the wires. Having said that the generator does pack up but if someone has fiddled with it they may have not refitted it correctly. It can be removed by following the instructions in the manual.
It is located at the back of the cylinder head and has just two wires. These run to the revcounter and connect at the back. It is a self contained system.

[Doherto]

As I am just re installing my dash i thought i could measure the voltage on the wires connected to the rev counter for you. Unfortunately it does not make much sence. On tickover i measured less than a volt which alternated between posative and negative. And DECREASED as the revs increased. The revcounter generator is positioned as per Martecs post and the two wires that connect to it go directly to the rev counter and thats it. If the wires are not broken or bad connections, either the rev counter generator is not providing an output, or, the rev counter is faulty. I will try again this afternoon to see if i can get some voltage measurements that will allow you to prove which is faulty, assuming your wiring is ok. Does anyone know what the output of the rev counter generator should be?

[martfill]

Thanks to you both I'll do some serious detective work the week end, Thanks again

[Doherto]

Martin, i cannot reason or explain the following but at least i have some useful information for you. The output from the rev counter generator which is positioned at the rear of the offside cam cover is around 7 volts AC on tickover and raises when the revs are increased. I cannot documemt any additional values as my rev counter is not connected yet. The wires on my 240 are black/blue and black/brown and form a seperate circuit from the vehicle wiring of 12volts DC. Quite simply, if the output is not present on the generator, the generator is faulty, if it is present on the input to the rev counter, the rev counter is faulty. Hopefully this makes sence, if not, feel free to PM me and i am happy to help by phone. Tony

[martfill]

Thanks for that Tony I'll investigate the week end and see what transpires, thanks again I may well be in touch soon.

[martfill]

Thanks for your help it turns out that one of the electrical connections on the rear of the cam shaft had snapped , so I simply soldered a new one and the Rev counter now works a treat.
Many thanks