Grounding the horn switch

[tpspeier]

The horn on our new (to us) 2008 AR230 didn't work when we bought it a few weeks ago. I purchased and installed the newer Yamaha model horn per this thread: https://jetboaters.net/threads/pre-2016-horn-replacement-banish-the-duck.21549/.

After removing the old horn, I saw that the spade connectors at the horn's location were a little corroded. I replaced the connectors and installed the new horn and it didn't work. I know the issue isn't the horn since I direct connected it to the battery and it worked fine. I suspect the issue is either in the wiring or the switch -- I ran out of time and didn't get a chance to test out the voltages at each point to determine the point of failure.

However, while I was behind the helm I noticed that my horn switch only has two wires connected to it: a line in wire and a horn out wire, and there is a third terminal with no wire attached. In looking at the wiring diagram for the boat, it shows a third connection to ground (presumably the third terminal on my switch).



I don't see a dangling ground wire behind the switch panel, so it's not clear to me if the horn switch was ever grounded. Does anyone know if there is some reason why the horn switch wouldn't be grounded?

 

[212s]

Based on previous experiences with horn replacements, there should be a dedicated ground from the horn back to the negative bus or battery, and the positive is routed through the switch for momentary connection as needed to "honk" the horn - the switch closes the circuit momentarily to sound the horn just like a car horn. I think the diagram above is correct as there is a need for a ground line into the switch for backlighting of the switch itself at night - the ground is NOT for the horn circuit, just lighting.

If it doesn't work, I suspect a corrosion issue somewhere else along the wiring - or the grounding line is corroded.

 

[zipper]

Does the 12vdc accessory outlet on the dash work? It shares a (black) ground wire with the horn. Per the schematic.

 

[tpspeier]

I think the diagram above is correct as there is a need for a ground line into the switch for backlighting of the switch itself at night - the ground is NOT for the horn circuit, just lighting.

This makes sense because the switch does not light up unless it's being pressed.

Does the 12vdc accessory outlet on the dash work? It shares a (black) ground wire with the horn. Per the schematic.

A prior owner had replaced the outlet with a USB charger and it works. The ground wire shown in the schematic terminates at the USB charger on the boat -- it doesn't continue on to connect to the horn switch.

If it doesn't work, I suspect a corrosion issue somewhere else along the wiring - or the grounding line is corroded.

This is likely the cause. The old spade connectors were corroded when I removed the old horn. I replaced them but the wire may very well be corroded. I'm away from the boat now so it will be Friday/Saturday before I can make further progress on this. At this point, I'm thinking of just replacing the switch and the wiring just to be done with it. It should be easy enough to replace both of them.

 

[tpspeier]

Replaced the horn switch this weekend and the new horn works.

 

[biffdotorg]

Glad that worked for you. The horns on these boats has got to be the worst design. I have replaced twice, and have resorted to a handheld horn since it failed most recently. You have inspired me to try again.

 

[tpspeier]

I was so excited when the horn started working I sounded it over and over again until my wife came out of the house asking if something was wrong.

In any event, it actually was a pretty painless project following the steps provided by msavold in the other thread. I used this switch: https://smile.amazon.com/gp/product/B08SW3VFC5/ref=ppx_yo_dt_b_asin_title_o05_s00?ie=UTF8&psc=1. The new switch was slightly larger than the old switch so I filed the hole slightly to get the switch to fit.