120 Johnson Trim & Tilt Gauge

[noclaim]

1989 120TLCE trim and tilt gauge quit working. Lever sender on transom mount is free. Anyone have a quick test at the gauge with a voltohmeter?

 

[Hooty]

Re: 120 Johnson Trim & Tilt Gauge

I would think you could use your vom and check the voltage at the sending unit. If the sending unit is working, the voltage should go up and down as the lever is moved up and down.<br /><br />c/6<br /><br />Hooty

 

[Joe Reeves]

Re: 120 Johnson Trim & Tilt Gauge

James.... With the ignition key in the on position, run a small jumper wire from the "S" (sensor) terminal of the gauge to a ground. If the meter pegs full up, the gauge is okay and you have power to the gauge. In which case, the most likely suspect is the sender.<br /><br />To test the sender, trace the wires back from the sender to a plug in connector, and disconnect it. Hook up a ohm meter to the sender wires, set the meter to low ohms, then move the sender lever up and down. You should get a smooth movement on the meter with no dead spots or jerky movement.

 

[noclaim]

Re: 120 Johnson Trim & Tilt Gauge

Thanks Joe. Turned out it was the sending unit. All is fixed and working. James E.

 

[jeepers94]

Re: 120 Johnson Trim & Tilt Gauge

J. Reeves or others:<br /><br />The trim gauge on my 90 HP, 90 model Johnson gave out suddenly after experiencing one occassion of on/off operation. Used the jumper technique described here and the gauge pegged full up. Moved to the sending unit and seemed to get a smooth increase & decrease as I moved the sending unit up ??????. Keep in mind I am a novice with multimeter. I used the resistance setting? The only thing that seemed unusual was that at rest (full up) there was no reading. Should there have been? Is this what you would call the jerky movement because it registers suddenly as you start moving it down???

 

[Hooty]

Re: 120 Johnson Trim & Tilt Gauge

I guess when you say "full up", you mean the l/u is trimmed full up and the gauge is reading full down. When you start moving the l/u down, the gauge jumps up. Is this correct?<br /><br />c/6<br /><br />Hooty

 

[jeepers94]

Re: 120 Johnson Trim & Tilt Gauge

The gauge is "frozen" at the down postion. It only moved up when I "jumped" it to ground and dropped right back down when I removed the jumper. <br /><br />Full up as I described is when the engine would be trimmed full up but I was actually maually moving the sending unit while watching the multimeter display. The trim gauge never moved but the multimeter did show slow adjustments with the exception of at the point it reached the equivalent of full up when there was no reading. I am not sure thats any clearer.

 

[Hooty]

Re: 120 Johnson Trim & Tilt Gauge

I think I understand.<br />It sounds like both the gauge and sending unit are working, just not together. Switch your multimeter to "DC" volts and a scale that reads 12 VDC. Connect one lead to the "S" terminal on the gauge and the other to the "G" terminal. With the switch "on" move the sender arm up and down and see if volt meter moves. If it doesn't, switch the leads on the gauge. If it still doesn't move, start looking for a loose connection.<br /><br />c/6<br /><br />Hooty

 

[Joe Reeves]

Re: 120 Johnson Trim & Tilt Gauge

Jeepers.... The ohm scale meter reading usually has the infinity reading on the left side of the scale, with the low reading (0,1,2,3,4 whatever ohms) to the right side of the scale.<br /><br />If when you release the spring tension on the sender assembly, which would be the full up position, the meter needle swings (jumps) to the extreme left side of the scale (infinity), the sender is faulty.<br /><br />Having the ohm meter set to the low ohms scale (R1), there should be a smooth transistion from approximately one (1) ohm to approximately ninety (90) ohms.

 

[jeepers94]

Re: 120 Johnson Trim & Tilt Gauge

Hooty, here is what I found. Using the voltmeter, while manually adjusting the sending unit, there was no change in the current regardless of the combination of leads I touched.

 

[jeepers94]

Re: 120 Johnson Trim & Tilt Gauge

Sorry, I jumped the gun. I went back and ran the test again...I remembered I had the sending unit disconnected at the plug in connector. <br /><br />The current does change (decreases from ~9.6-8.5) as the sending unit is moved down.