1979 (?) Mercury 7.5 - Charge 12V battery?

[griffel]

Hello from Denmark/Europe everybody

I just got a fine old Mercury 7.5 Electric from my uncle.

http://peecee.dk/upload/view/249220
http://peecee.dk/upload/view/249218
http://peecee.dk/upload/view/249219

It has not been operated for a while, but it starts and runs like a dream
I have changed the impeller so the cooling is ok now.

The engine must have been operated with some kind of remote, because the steering handle is missing

And the wiring is somehow alternative:
http://peecee.dk/upload/view/249215
The two brown cables are for the electric starter and the red comes from here http://peecee.dk/upload/view/249216
Is that a voltage regulator for charging a starter battery?
I have measured the voltage on the red cable and it is between 8 and 21 Volts DC(?) depending on how fast I am running the engine. Is the regulator defective then? Or am I doing something wrong?

Thanx for any input!

Greetings from Denmark!

Jakob

 

[jfm]

Yes that is a 1979, from the decals
I think your theory is right: the orange square box is a voltage regulator, and it is not working. The red wire conection to this regulator is original Mercury - the rubber cover over the terminal and the little rubber tab on the rubber cover are original items from the 1979 era

If you look thru US websites (or contact Grubbs at oldmercs.com you can probably get an original regulator and a 2nd hand tiller arm. Otherwise you could fit a non-Mercury regulator from an auto shop.

Good luck