Finding tach wire in 1972 Selectric control box

[GrahamD]

I want to install a tachometer for my 72 Evinrude 50hp with the Selectric push button control box.

I have learned that the signal wire is grey and terminates in the control box without being attached to anything. My problem is that I can't find the wire without completely disassembling the control innards and I am reluctant to do so without some guidance as I don't want to damage the button mechanism.

Does anyone know whether there is a way to locate the tach wire without the removal of the button mechanism and if not is there any suggestions/cautions relating to its removal that I should consider?
Thanks.

 

[racerone]

Is there a cover that comes off ???---Held on with 6 screws ?

 

[GrahamD]

Thanks for the reply. Yes. I have removed the cover as well as the plate around the buttons and can see down into the control box but can't see the grey wire. It could well be further down but it is not obvious how to access it.

 

[fdrgator]

Should be in there without major disassembly.