Tilt &Trim problem on 120hp Johnson

[ET1]

I have a 1990 Johnson 120HP and I need a schematic (not a wiring diagram)of the wiring for the tilt and trim circuits. The motor won't run unless I jumper the circuit in the relay box, then the motor runs fine - up and down. I suspect a missing or corroded ground wire connection but I don't know the color codes or where the connections are made. I have a wiring diagram but it's no help because the color codes can't be followed to their source or origin.

 

[Bradster941]

Re: Tilt &Trim problem on 120hp Johnson

On the control wiring, Blue is up, Green is down, red is hot.

 

[JB]

Re: Tilt &Trim problem on 120hp Johnson

Going to Johnson Troubles.

 

[Walker]

Re: Tilt &Trim problem on 120hp Johnson

Test the red wire coming into the control box with a voltmeter. Then test it again while pushing the trim switch either up or down. I've worked on 2 of those 120's where the power wire (red) to the trim circuits was bad. Got a reading of 12.8v static but when the switch was pushed volts dropped down in the 8's

 

[ET1]

Re: Tilt &Trim problem on 120hp Johnson

Thanks to those who offered advice. This was my first post and I think I put it in the wrong place but I'm glad you folks found it.<br /><br />LJG Walker, I think you're right. That's exactly how it's acting. That's why I was hoping to find a schematic so I could tell where the connection and/or splices are made. The problem is so intermittent, when it doesn't work, neither the T&T switch on the throttle handle nor the T&T switch on the lower engine cowl works. <br /><br />I think I'll have to start breaking the harnesses open to trace the wires. Sure hate to do that but ......