1975 Merc 650 tach wiring

[Rick_Banshee]

Hello everyone! I recently purchased a 1975 merc 650 Ser. No. 7030690 and have installed it on my 15' Banhsee ski boat. The tach wires are plugged in to the mercury control box, black, brown and white wires hoever they are not connected to the tach. The tach is a Quicksilver and I believe an alternator drive, the white wire has a light bulb so that one is obvious and there is a jumper lead from the white wire possibly for a light on the speedometer, but he other 2 I don't know. Also, the positive pole on the tach has a short jumper lead on it!? Any help would be appreciated and pictures woth a thousand words. Thanks.

 

[haventaclue]

Black is neg.,Brown is sig.,White is 12v.The pic is of a Merc tach where the black wire goes to the pos+ and the brown to the neg.- with the white the loop for the lamp.
If you have a standard tach with a pole adjustment,the black to neg- post,white to pos+ post and brown to sig. post and set the adjustable pole at 6P

 

[Rick_Banshee]

Black is neg.,Brown is sig.,White is 12v.The pic is of a Merc tach where the black wire goes to the pos+ and the brown to the neg.- with the white the loop for the lamp.
If you have a standard tach with a pole adjustment,the black to neg- post,white to pos+ post and brown to sig. post and set the adjustable pole at 6P

Thank you for the quick reply! I am on my way to try the connections now. Will let you know the results!