richardcranium
Cadet
- Joined
- Mar 9, 2011
- Messages
- 8
Re: Mercury Thunderbolt tach help
Hi from Australia all, this is exactly the thread I needed, having just come to the instrument section of my project boat. Mine is the 1150 Thunderbolt ign. model (75 possibly?) and it still had the original tacho (the one on ebay in post 10) and loom that plugs into the front of the control box. The wires weren't connected to the tach however. The back of the tacho only has 2 terminals 1 marked "- negative", the other "+ positive" and a centre stud marked " T bolt" which is a ground to the casing it appears. At the engine end the brown wire from the tach loom is connected to the switchbox. There is no brown on the rectifier so I'm assuming this is the old setup where the tach signal comes from the switchbox? Also is there any way of testing the old tacho to see if it works, and even if it did it seems the general consensus is to ditch it and go for a newer stator driven one? Finally, what wire goes where on the tacho I have? thanks guys
Hi from Australia all, this is exactly the thread I needed, having just come to the instrument section of my project boat. Mine is the 1150 Thunderbolt ign. model (75 possibly?) and it still had the original tacho (the one on ebay in post 10) and loom that plugs into the front of the control box. The wires weren't connected to the tach however. The back of the tacho only has 2 terminals 1 marked "- negative", the other "+ positive" and a centre stud marked " T bolt" which is a ground to the casing it appears. At the engine end the brown wire from the tach loom is connected to the switchbox. There is no brown on the rectifier so I'm assuming this is the old setup where the tach signal comes from the switchbox? Also is there any way of testing the old tacho to see if it works, and even if it did it seems the general consensus is to ditch it and go for a newer stator driven one? Finally, what wire goes where on the tacho I have? thanks guys