Wiring 2003 Johnson 90 hp

[adominique0313]

Ok well I have asked a couple of times here about this. On top of the motor there is a cover. It is covering up wiring that is yellow with grayish line. I have been told it is the tach however, I pulled apart my boat today and all the wires going to the tach are plugged in. And none of them are yellow with grey stripe. All the wires from the tach are smaller wires. This yellow and grey wire looks like it is coming from the top of motor and gets plugged into two barrel looking connectors. Then comes down the side of the engine and into my battery compartment. It has been cut off there. It appears to have 7 or 8 volts in it. Any ideas where this would get hooked up?

 

[Chris1956]

yellow/grey is one of the stator wires, and is usually used to drive the tach signal, however, it's color changes to grey, at the voltage regulator. A simple tach would have grey, purple and black wires on it, with the grey wire having the tach signal.

 

[Bosunsmate]

photos

 

[adominique0313]

No Title

photos

 

[V153]

I think the important question we need to ask is ... Does the motor run? And/or does the tach work? If so put a wire nut on that lead'n be done with it.

 

[adominique0313]

Motor does run. Tach does not work

 

[adominique0313]

I think the important question we need to ask is ... Does the motor run? And/or does the tach work? If so put a wire nut on that lead'n be done with it.

Motor Runs, Tach does not work

 

[adominique0313]

anything?

 

[Chris1956]

Check continuity from grey wire at VR to grey wire at tachometer. Resistance should be zero, end-to-end on the grey wire. There should be no continuity to ground, once grey wire is disconnected from tach.

Does motor charge?

 

[adominique0313]

Check continuity from grey wire at VR to grey wire at tachometer. Resistance should be zero, end-to-end on the grey wire. There should be no continuity to ground, once grey wire is disconnected from tach.

Does motor charge?

Not sure of the VR I think my engine has the grey wire coming from the rectifier. I am not getting any volts ac or dc. not sure what the next step is? Is there a way to check the tach its self? I have volts coming out of the yellow wires on the rectifier just not the grey wire. also I did every thing you told me to do and there is not any continuity to ground and the resistance is at 0. The motor does charge the battery if that is what you were asking? I get about 13.75 volts at the battery when running at idle and 12.45 when motor is off just testing the battery.

 

[Chris1956]

OK, the motor charges and the grey wire is not open or shorted. The next step is to look for an AC voltage on the grey wire, when the engine is idling. I am not sure what range voltage you will see so start with a high AC scale and drop it down until you see some AC voltage. If no voltage, recheck the grey wire connection to the Voltage Regulator or Rectifier. I would be surprised if you have just a rectifier, BTW. If you have the AC voltage on the grey wire at the tach, when the engine is running, perhaps the tach is bad.

 

[bob johnson]

seems to me that the yellow w/grey wire goes from the rectifier to the stator....

beyond that I am totally confused about the description of the wire...running"down the motor to the batter box"....what wires ever go to the battery box( from the motor) except the red, black battery cables???

 

[adominique0313]

OK, the motor charges and the grey wire is not open or shorted. The next step is to look for an AC voltage on the grey wire, when the engine is idling. I am not sure what range voltage you will see so start with a high AC scale and drop it down until you see some AC voltage. If no voltage, recheck the grey wire connection to the Voltage Regulator or Rectifier. I would be surprised if you have just a rectifier, BTW. If you have the AC voltage on the grey wire at the tach, when the engine is running, perhaps the tach is bad.

Okay, I have AC voltage at the grey wire at the tachometer. the more throttle I give the higher the voltage goes... does this mean a bad tach? if so how to I get another tach that has the same plug in the back?
Thanks

 

[adominique0313]

seems to me that the yellow w/grey wire goes from the rectifier to the stator....

beyond that I am totally confused about the description of the wire...running"down the motor to the batter box"....what wires ever go to the battery box( from the motor) except the red, black battery cables???

if you look at the picture in this post it has like 4 yellow/grey wires are hooked up except for one it looks like it went down the motor to the battery box and hooked to a "guest" isolator how ever I bought the boat used and the Guest isolator was broken and the wires were cut that went to it. I believe it charged two batteries at the same time as the engine runs. I don't know that for sure but that is my best guess. So I guess the question is what is the yellow/grey wire and why is it putting out 10 volts? does it have anything to do with the tach?

 

[adominique0313]

got it figured out as far as the tach goes, the tach is bad I tapped it a little bit and it went up, rev the engine and taped it and it went up more. but the needle sticks so I will have to try to find a new one