Need help installing tach on 50hp tldi tiller engine

[shoes]

I just got this motor installed a week ago and I bought a tach with it so I could check my rpms and use the diagnostics. Along with the tach i got an extension cable so I could mount the tach in a remote area. The cable has two wires in it, a black one and a white one. The dealer's tech talked me thru the process and while on the phone I found a plugged white wire in the belly area of the motor on the stbd side. I plugged the extension cable's white wire into that, and the plugs were compatible. The black wire in the cable has a ring terminal at the end, so I assume that's a ground wire. There was a tapped but unused hole near the front of the engine so I threaded a screw into that hole to seucre the ground wire. When I put a voltage meter across these wires I get .33 volts when the key is on.

With these wires hooked up, the tach needle doesn't budge when I turn the key on, nor does it budge when the engine is running. Did I hook the wires up wrong or is it possible the tach is bad? One clue it may be the tach that is bad is that the needle points straight down instead of to the zero rpms at about 7:00 on the dial.

 

[pvanv]

Re: Need help installing tach on 50hp tldi tiller engine

What tach do you have? Is it the TLDI-specific tach? Is the poles switch set correctly (4)? Does the tach read incorrectly when all power is off, or does it read Zero then? The proper harnes should have yellow and white wires. Did you connect the harness as in your owner's manual at http://www.tohatsu.com/tech_info/manuals.html ?

 

[shoes]

Re: Need help installing tach on 50hp tldi tiller engine

To answer your questions: yes it is tldi specific. The dealer's mechanic said the pole switch was set already, but I cannot see anywhere on the back of the tach to verify this. Where is the pole switch on the tach? The tach needle never moves from almost a straight vertical position pointing downward. When I turn the key on, I get a reading of .33 volts across the white/yellow wires going into the tach. The owners manual and the instructions with the tach give no information about where to make the wiring connections under the hood.

 

[pvanv]

Re: Need help installing tach on 50hp tldi tiller engine

Are you connected to white/yellow at the motor? If so, might be time to drop by the dealer to make sure everything is connected properly.

 

[TOHATSU GURU]

Re: Need help installing tach on 50hp tldi tiller engine

Shoes,

Is this the actual Tohatsu tach or is it an aftermarket tach that is supposed to work on a Tohatsu TLDI?

 

[shoes]

Re: Need help installing tach on 50hp tldi tiller engine

Paul and Guru, thanks for keeping up with this question. I just got back from vacation so now I'm back on this problem. To answer both questions: Yes it is a dedicated Tohatsu TLDI tach p/n TO1918B mfgr on 4/24/12. It has "TLDI" right under the Tohatsu name on the face plate. I see no setting screw on the back to change from 4P to 6P etc.

The white and yellow wires coming from the tach are in a male/female fitting which mates with the extension cable the dealer gave me. There is no way to reverse these wires. The extension cable converts the colors from white and yellow to white and black. At the motor end the black wire has a ring terminal installed so I assume that's the ground. I grounded that to the motor and plugged the white wire into a plugged white wire that was in the belly pan on the port side of the motor. I did this while the dealer's mechanic talked me through it. The dealer is about 60 miles away and this was happening while I was getting the boat ready to take on vacation. When I turn on the key, I get .33 volts flowing thru the wires to the tach. The tach needle doesn't budge when I turn the key on or start the motor. I think my next step will be mail the tach back to the dealer to let them test it and replace it if it's faulty. The manual says to mount the tach at a 50-80 degree angle, but changing the angle makes no difference.

 

[Only120jman]

Re: Need help installing tach on 50hp tldi tiller engine

What did you find out about the wires? Was the tach bad? I'm having similar issues with a tldi tach.

 

[pvanv]

Re: Need help installing tach on 50hp tldi tiller engine

What did you find out about the wires? Was the tach bad? I'm having similar issues with a tldi tach.

Don't forget to supply +12v power to the meter...