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MG Midget and Sprite Technical - RVC Tacho

Stupid question!
Is the post to which the signal wire attaches supposed to "float" I have a bad connection somewhere which causes the needle to alternately bounce around all over the place, do nothing, or register correctly! Wiggling the signal wire whilst driving along allows me to switch randomly between these modes. I thought it was the bullet connector but it seems fine so assume I have a bad connection between my "wobbly" post and the electronic innards. Any advice?
Matt1275Bucks

It certainly sounds like something has come adrift.

Easy enough to open it up and have a look.
Dave O'Neill2

Matt,

If it was the bullet connector the car would misfire in tune with the tacho fluctuating.

The white wire carries the spark, the tacho senses the speed to give you your output, without disrupting the power.

Does anything else flicker with the tacho ? - if so have a look at all the items fed by your voltage stabiliser - they are 'powered' by the green wires.

Malc
Malc Gilliver

No misfire or any other noted electrical gremlins. I omitted to say I have an alternator and electronic ignition. I'm sure it's the bullet post to tachometer connection as fiddling behind the dash when driving affects things. Hence my question as to whether the bullet post should be rigid or wobbly?
Matt1275Bucks

Malc

The RVC tacho doesn't have the white wire looping in and out, it just has a single 'pulse' wire from the coil.
Dave O'Neill2

Thanks Dave, didn't know that.

So if he has an RVC, not an RVI and the wire is loose he has his answer then.....


Malc
Malc Gilliver

Thanks, But going back to my question, "is the post for the signal lead supposed to be rigid?" Is any one else's a bit floppy?
Matt1275Bucks

Matt,

My spare RVC has the bullet and spade exiting via a sort of sponge gasket in the back of the case.

The spade is rigid the bullet has only the slightest of sideways movement - none in or out.

R.

richard boobier

Lovely, thanks Richard. I'll whip my tacho out and see what I can find.
Matt1275Bucks

This thread was discussed between 10/09/2013 and 12/09/2013

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