Can a two wire alarm replace a three wire alarm?

I have an 89 120 hp Johnson that has the VRO disconnected and a three wire alarm with the tan wire pulled out of the epoxy. Can a two wire alarm be wired up to warn me of overheating. If it can would you describe the proper wiring procedure. Thanks, John Actually there are two purple wires connected together, a black wire and the tan wire.

When you open the plug that comes from the VRO no alarm will sound due to no oil.------The overheat alarm still works !-----No fancy wiring needs to be done.

Racerone, are you saying that with the tan wire disconnected the alarm will still sound if the motor is overheating. Do I just cut the end off of the tan wire? John

He's talking about the alarm horn itself.
The black is ground, the purple is +12v when key is on, and the tan is the triggering signal.

When the triggering signal goes to ground, the alarm sounds.

On the two wire horn, you have +12v and tan wire. When the tan wire goes to ground, the circuit is completed, and the horn sounds.

On the three wire, you have 12v and ground, and the innards of the horn chirp when 12v is first applied. That is just to let you know the horn works. Again, when the tan goes to ground, the alarm sounds.

So, just test it. Wire it up like I described, go back to the engine and ground the tan wire from the temp switch to see if it works.
The innards of the three wire horn may prevent it from working just with the purple and tan connected.

I have a two wire horn if you need one.

Disconnect the plug to the VRO warning circuit.-----------------------Then find the tan wire on the cylinderhead.-----------Turn key to " on " and ground tan wire to cylinderhead.--Horn should sound.

Daselbee, racerone, hooked up as mentioned and horn sounds at the powerhead, thanks for your help. John