2004 115 4 stroke - constant alarm

[wmocarsky]

2004 115hp Johnson 4 stroke:

When I turn the ignition key to on (before cranking motor) the alarm horn sounds continuously. When I start the motor, the 'system check guage' never attempts to cycle through its lights (no lights ever light).

With the key just 'on':

I have checked the ground (tan wire) on the alarm horn - it does not go to ground. When I jumper the +12V to the alarm horn disconencting the tan wire - horn doesn't sound - so assume horn OK

At the connect to the alarm horn, I have 'looked back' towards the motor. The return wire (not +12V) has some continuity to ground, but it shows some resistence.

Can the 'system check guage' be bad and cause this?

If someone can tell me where the temperature/oil sensors are, I can check them. If there is only 1 wire on them, should it be ground? If 2 wires 1 ground 1 not?

If it is not any of those other than a shorted wire - could it be the control module (I HOPE NOT).

Thanks for any suggestions

[boats.net]

The temp sensor is a two wire, the oil sensor is a single wire. I am unsure of the locations. Usually the temp sensor is located in the head.

[wmocarsky]

Please some more help

The temp sensor is a two wire, the oil sensor is a single wire. I am unsure of the locations. Usually the temp sensor is located in the head.

Found the temp sensors - assume there are 2(?) each having 2 black wires. Any idea what the resistance should be when I disconnect them at the connector and look back at the sensor?

Also think I found the oil pressure sensor - appears to be located near the front of the motor having 1 wire that looks like it has a non removable spade connector which is threaded on the sensor. Again any idea what should be the resistance when measured to ground?

Anyone know if a bad system check guage can cause this issue?

Thanks

[boats.net]

Unfortunately I do not have access to the ohm readings for this model.