OMC Cobra Trim Sensor

[11968417]

The trim gauge on my 1990 OMC Cobra I/O is pegged to the right. When I turn the key on, the needle drops back alittle (1/4 inch) to the left. The gauge light works and my ohm meter indicates I have power at the gauge. I unplugged the sensor at the connection by the engine and tested for resistance, there is none. Then I looked at the outdrive on the starboard side at the sensor itself. There appears to be a small arm, attached to the sensor, in the up position. There is tension on this arm but when I pull it down the needle on the gauge does not move. The arm is not attached to or touching anything. Do I have a bad sensor or is not connected properly? [/LIST]

 

[moderator1]

Re: OMC Cobra Trim Sensor

Moving to I/O questions.

 

[CCrew]

Re: OMC Cobra Trim Sensor

The sensor is nothing more than a potentiometer. Voltage is sent across it,and the voltage change is based on the value across the slider (driven internally by the arm). To check whether the I/O unit is bad, you should be able to place the ohmmeter across the two terminals, and move the arm and the resistance should change. If not, the sender is bad. Part number for that sender is 0984748 and it lists for $73.31 if it indeed needs replacing. Don't throw the old one out until the new arrives, as the arm, clip, spring, and electrical boot are all separate parts and will need to be switched to the new sender. <br /><br />Hope that helps!<br />-Roger

 

[rodbolt]

Re: OMC Cobra Trim Sensor

hello<br /> the hard part is removing the wire holding clip and removing the wires from the transom shield. get a service manual. read it and study it before attempting it. you will be glad you had forknowledge of what your trying to do. its not rocket science there just is no working room.I usually wipe the new sender wire plug with OMC gasket sealing compound at the transom sheild but dishsoap may work if there is no corrosion<br />good luck and keep posting

 

[andrewgroup]

Re: OMC Cobra Trim Sensor

Just installed the same part and it came with a replacement clip, and a new grommet and the sending unit had the arm on it. I had one of the bolt head break off trying to remove them. I had to drill it out. I recommend you start applying some breakfree spray now. Once I new I had all the right parts, and it worked properly by attaching it to the connector and testing it first. I cut the existing wires off and pull it through the rubber grommet. I use a long pair of needle nose vise grips to remove the existing gromet. The wires push on the new sender need to be pushed through grommet before before you install the gromet into the hole. I used silicone spray as a lube and I grabbed the grommet from the inside and pulled it snuggly into place. The clip holds it in place afterwards. <br /><br />Good Luck....

 

[11968417]

Re: OMC Cobra Trim Sensor

I appreciate all of the information I have received and if I need to replace the trim sensor this guidance will be very helpful. In my original posting I identified that there is a small arm, spring loaded and attached to the sensor. My guess is the outdrive moves that arm which indicates the position on the trim gauge. The arm is not touching anything so if my guess is correct what is the arm suppose to connect to?