tach signal 2002 Mercury 115 ELPT4S

[JeepinGunGuy]

My son bought a pontoon with a 115 Mercury on it and the tach is inop. The previous owner swapped the 115 for some kind of a Yamaha 40 or 50 HP he couldn't remember. I have not seen the boat in person yet so I don't know if the tach signal is missing or set wrong. Can anyone tell me what wire the tach signal is and how many pulses to set the tach for?

 

[JeepinGunGuy]

I think I may have muddied the waters with too much information. Does anybody know what the tack signal coming from the motor will be and possibly what color the wire will be on a 2002 Mercury 115 ELPT4S?

 

[GA_Boater]

The muddiness is no knowing what motor is on the pod. Can't tell if a Merc was swapped out for a Yammie or the other way around.

When you see the toon, check for the wire colors on the tach. It's going to have 12 volts, ground, possibly instrument light and a signal wire. The first 3 will be routed from instrument to instrument, the signal wire will be a single wire to the remote control or to the harness between the motor and dash.

 

[Texasmark]

My son bought a pontoon with a 115 Mercury on it and the tach is inop. The previous owner swapped the 115 for some kind of a Yamaha 40 or 50 HP he couldn't remember. I have not seen the boat in person yet so I don't know if the tach signal is missing or set wrong. Can anyone tell me what wire the tach signal is and how many pulses to set the tach for?

Mercury is a grey wire from the 8 pin connector in the engine and comes out on pin 5. Dial on 6 on most tachs. Grey wire to ground...black wire, 3v (pulsating) DC (scale on meter) minimum at low rpms. As rpms increase amplitude will increase. Manual isn't clear as to what rpm the 3v minimum is recorded. May be 1000 as these alternators don't put out much prior to 1000.

 

[JeepinGunGuy]

Mercury is a grey wire from the 8 pin connector in the engine and comes out on pin 5. Dial on 6 on most tachs. Grey wire to ground...black wire, 3v (pulsating) DC (scale on meter) minimum at low rpms. As rpms increase amplitude will increase. Manual isn't clear as to what rpm the 3v minimum is recorded. May be 1000 as these alternators don't put out much prior to 1000.

Texasmark thank you sir, it's not getting a signal to the tach at all. The wiring is a butchered up mess, none of the gauges work. Typical kid buy a shiny red thing and expect dad to save the day and make it all right again. Do you happen to have a wiring schematic or pin-out chart for this motor?