Horn/ Alarm Ck? F80

[Marc Kruse]

I've read several posts on here were it says to ck it just pull your kill sw. and turn the motor over and it should go off. I also read one or two that said this doesn't work with all motors. I tried it and it didn't work on mine or I have a bad horn.

If I just ground the oil pres. sw. shouldn't it go off also or do I need to remove the wire from the sw. and just ground the wire?

Also can the same type test be done on the Water Temp Sensor by connecting the 2 wires to make the horn go off?


This is a 2001 F80LTRY with a 703 control and a single Analog Tach.

Thanks in advance

[boscoe99]

You can remove the oil pressure switch lead and ground it to the block.

Or, disconnect the thermosensor and jumper the harness side wires with a 220 ohm resistor.

Start the motor. Don't be impatient. Let it idle for a while. The alarm should sound.

[Marc Kruse]

Thanks again Bosco99
When I ground the Oil Pres. Sw wire the horn should sound immediately because all your doing is creating a ground for the horn which has 12v to it when ever the key is on right?

[boscoe99]

What makes you believe that you are grounding the horn?

[Marc Kruse]

I was thinking because it only had one wire and when you grounded
It to the block it was creating a circuit which made the horn blow.

[boscoe99]

The ground is applied to the CDI, not the horn. The CDI applies the ground to the horn. There may be a delay built into the CDI.

[Marc Kruse]

Ok
Well after 5 min grounded to the block and no horn. Suggestions ?

[rodbolt17]

some of the CDI's wont recognise the oil warning until the engine RPM exceeds about 2000 RPM at least once during that key cycle AND engine temp is above 113*F.
sounds stupid but I did not design it I just have seen it.
on some engines,mostly carbed ones, if engine RPM never exceeds 2000 RPM the oil warning never works.

[Marc Kruse]

Thanks Rodbolt
I'll hook up the muffs today and get it warm and test it again.
I know it worked because when I got the motor 2yrs ago it had been sitting up and I had to clean the carbs to get it running and when I got running it wasn't peeing and after running it a few minutes trying to clean out the pisser the alarm when off. New water pump and stat and she's run fine for 2yr's

[boscoe99]

If the motor is below 113 degrees F it should sound the low oil pressure when at idle after a short period of time. If above 113 it has to be above 2000 for a period of time. About a minutes time at least. We think.

There is very limited Yamaha systems descriptions and theory of operation. To make it worse, an EFI model will have different threshold criteria than will its predecessor with carburetors.

What was Yamaha thinking? Oh, they weren't.

It might be easier just to get a resistor and use it to fool the motor into thinking it is over heated.

[Marc Kruse]

Ok Guys
Test complete
I put it on the muffs an let warm up, grounded the OPS wire and when it hit 2000 the alarm went off.
So to ck the temp sensor I just turn the water down and let it warm up until the alarm went off.
So at this time everything is good
I want to thank everyone for their help again
BTW this is a great place for info