115 Overheat Alarm

[modernrocketry]

I've got a 115 Powerhead (mated to a turbojet)

The overheat alarm sounds the moment the key is turned on. The engine is cold.

Any suggestions please?!?!

 

[ezeke]

Re: 115 Overheat Alarm

The horn should sound for one second when the ignition switch is turned from the stop position to run or start to test the horn. It does not test the warning system wiring, just the horn.

If the horn continues to make a constant beep, disconnect the tan wire and if the horn continues to sound, replace the horn.

 

[HighTrim]

Re: 115 Overheat Alarm

If the horn stops, you will need to test the sensor components such as oil tank, heat sensors, etc...

This is done by removing the TAN wire from them one at a time until the beeping stops. When it does, you have found the faulty component.

If the horn is in fact faulty, you will find them to be a bit overpriced in my opinion,

 

[modernrocketry]

Re: 115 Overheat Alarm

The horn does not stop.

I have disconnected the tan wires from each of the heat sensors and the the horn continues to sound.

Where can I get a replacement horn? Is the a diagram that shows where it is located and how to remove replace it?

 

[ezeke]

Re: 115 Overheat Alarm

The boat manufacturer will have placed the warning horn at the helm, either under the panel or possibly inside of the remote control.

Disconnecting the tan wires at the engine will not disclose the failure of the horn, the tan wire must be disconnected at the horn to assure that there is no ground anywhere on the alarm system wiring.

 

[modernrocketry]

Re: 115 Overheat Alarm

Okay -- Thanks for the clarification -- I'll try it tonight.

 

[HighTrim]

Re: 115 Overheat Alarm

sorry, my post was in addition to Ezekes, I should have been more clear, as in after you disconnect the TAN wire at the horn and the beeping stops as it should, the horn is fine and it is time to look to the sensor components.

 

[modernrocketry]

Re: 115 Overheat Alarm

Thanks for the clarification...

I disconnected the tan wire from the horn and the alarm stops.
I also disconnected tan wires from each side of the motor and the alarm still continues.

So at least I know the horn is good... and loud!

What do I try next?

 

[ezeke]

Re: 115 Overheat Alarm

There is a short to ground in the tan wire somewhere, possibly in the plug in the wiring harness.

Use your ohmmeter to test for a open circuit.

 

[modernrocketry]

Re: 115 Overheat Alarm

Solved the problem -- and maybe found another...
I spent hours trying to figure this one out.

finally, in frustration, I decided to tinker with it a bit and not think about the problem. I knew the oil tank was low (less than 1/4 left) so i filled it up and cleaned a few spots on the fiberglass.

I tried it again -- and alas the alarm stopped. It seems it was the oil tank (The boat sits differently on the trailer than in the water thus causing the sensor to activate) -- but my understanding of 1996 115 is that low oil is a series of beeps, not a constant beep. I'm glad I found it -- although I think I am partially deaf now.

Could the leads on the horn be backwards?