Need a little help with the warning horn system on a 98 E115TSLECM

[GatorMike]

This motor is not oil injected so the overheat horn is all I have to deal with. Let me give you a little background. My boat came with a Johnson J115TSLECM about 3 years ago the warning horn quit working. I never could get it working after that. That Johnson went bad on me and I lucked into a deal on the identical model Evinrude E115TSLECM. The swap was easy Just switch motors and plug in the Evinrude. I hoped the warning horn would magically start working but no such luck. I did put on a new keyswitch when I did the motor swap. This afternoon I hooked up 12 volts directly to the horn and it sounded so that is not the problem.

​If anybody is familliar with the 115 SPL model I would apreciate some guidance. I've tested the horn/buzzer and it works. Since neither my old Johnson or the Evinrude would sound the horn when the key is turned on I suspect it may be the wireing harness but don't have a clue how to troubleshoot this.

 

[Daviet]

Disconnect the sensor at the cylinder head, turn the key to the ON position and ground the HARNESS end of the wire, does the horn sound?

 

[GatorMike]

No, I just tried that and got no sound when I grounded the sensor wire.

 

[daselbee]

Do you have the Systems Check tach? If so, your horn will not sound with the above test unless the engine is RUNNING.

 

[GatorMike]

Do you have the Systems Check tach? If so, your horn will not sound with the above test unless the engine is RUNNING.

No back in the day when my warning horn actually worked you would turn the key to the on position and hear a short beep.

 

[GatorMike]

OK I wasn't getting much help on this problem so I did a little experimenting on my own. I unpluged the tan & purple wires that plug into the warning horn then grounded my test light to my accessary ground buss bar and put the point of my test light into the socket for the purple wire then switched on the keyswitch. The test light lit up. Am I correct in assuming that half of the circuit is working and the problem is somewhere in the tan ground wire?

 

[rothfm]

I believe you are right. You have verified the accessory circuit is providing power to the horn. Verify the horn ground is good. Attached is a diagram that shows it also.

Use a jumper and ground the Alarm tab at the horn just to verify it can work. Then you have to trace that Tan back to the motor, thru the harness checking for continuity.

 

[jakedaawg]

It will be much easier to just run a new wire.

 

[seahorse5]

Be aware that it is the SystemCheck gauge or tach with the 4 lights that contains the electronics to make the horn sound. If the gauge is bad somehow internally, the horn will not work.

 

[daselbee]

No back in the day when my warning horn actually worked you would turn the key to the on position and hear a short beep.

Uh Mike....we are not discussing the chirp which is normal when you power up.
We were discussing the test that was suggested....turn key on, ground sensor wire, and horn sounds.

I repeat, the horn will not sound unless the engine is running when performing this test. The light on the tach will come on, but the horn will not sound.

 

[daselbee]

OK I wasn't getting much help on this problem so I did a little experimenting on my own. I unpluged the tan & purple wires that plug into the warning horn then grounded my test light to my accessary ground buss bar and put the point of my test light into the socket for the purple wire then switched on the keyswitch. The test light lit up. Am I correct in assuming that half of the circuit is working and the problem is somewhere in the tan ground wire?

You are chasing your tail. Seahorse is right...you probably have a bad tach. Assuming you have a tach...you haven't answered my question yet....

 

[GatorMike]

I have a tach but not a system check tach.

 

[daselbee]

OK then, you might have the wrong horn...what wiring is driving your horn? The harness for a 98 engine should have an eight pin connector with all the tan warning lines coming up to it thru the harness. So how are you wiring the horn?

You have an older harness? If so, you might need the two-wire horn. It would have a purple wire and a tan wire. Purple goes hot at key on, tan wire provides ground when a fault occurs.

Newer Systems Check has all tan wires feeding into the tach, and a tan/blue wire from the tach to the horn. The horn has purple, tan/blue and black.

In this case, purple goes hot at key on, ground is provided on the black, and when the tach sees a fault on any of the 4 other tan wires feeding into it, it lights the proper light, and sounds the horn for ten seconds. Different operation completely. The engine must be running for the horn to sound for ten seconds.

To test the two wire horn, put +12v on the purple, and ground on the tan. Horn should sound.
To test the three wire horn, put +12v on purple, provide ground on black, and touch the tan/blue to ground. Horn will sound when tan/blue is grounded.

All of this circuitry has changed over the years...it just depends on what exactly you have.

 

[GatorMike]

I do have the 2 wire horn. I think this is where the confusion is comming from. The 98 J115TSLECM & E115TSLECM were the SPL models. OMC cut corners on that model (no VRO & no system check tach).

I have checked the horn itself by connecting the purple and tan wires to a 12V battery and the horn sounded.