some kind of sensor

[harbourseal]

Does anybody know what this sensor is for. Its located just behind the flywheel.

Something that looks like a magnet is pointed towards the flywheel.
The flywheel itself s a very deep cut in it.

My guess is that its for a Rev. counter.
Can anybody confirm?

://www.renault4.co.uk/forum/attachment.php?attachmentid=8154&stc=1&d=1363513304

 

[reidalpine]

surely must be the TDC (top dead center)-sensor ....-R.

 

[elch101]

It's for a diagnostics connect. Has nothing to do with the car, only used by garages for ignition timing,

 

[harbourseal]

Did they have those in 1978?
The engine is a 689 A7/10 from 1978.