2004 merc 525 with
 

warning horn trouble. The horn sounds three beeps about every 1 minute. All engine gauges read normal and coolant and drive oils are full. The engine is running fine but the horn continues. No codes are locked in the computer. Any ideas?

Re: 2004 merc 525 with
 

I had the same thing twice. First time it was the neutral switch, second time it was the cam sensor. Good Luck

Re: 2004 merc 525 with
 

Thanks, I'm going to take a look at it tonight. What ever happened to the good old days when if it didn't run it was spark or fuel????

Re: 2004 merc 525 with
 

I have same problem. Do you know how to check to see which is the cause?
thanks
roadrunner

Re: 2004 merc 525 with
 

I wanted to bring this thread back up to see if it was the cam sensor here and if so, can you tell me how you fixed it. Thanks.
KC

I have a buddy that has this same engine and problem today. What else should he look for besides the cam sensor and neutral switch?

Steve - John here hey does the engine go into guardian mode (activated) = engine power reduced

If NOT

3 beeps that are 1.5 seconds in length

Charge temp sensor failure
Cam sensor (rationale)
Oil Temp sensor failure
Coolant Temp sensor failure
Low sensor power and or Low battery voltage
fuel pressure sensor failure
Block (sea water) pressure sensor failure
can bus problem

If 3 beeps in length of 1.5 seconds and engine goes into guardian mode - power reduction mode

Throttle position sensor failure
oil pressure sensor failure
Battery range to high or to low

I am going to change my name to

Your source for OEM information and hopefully problem solving. Just messin or maybe not. lol

Lol, John, this is for another friend . I don't really know if it goes into guardian mode as he just fired it up on the hose for the first time since putting in new head gaskets and valve springs. It's a Baja 25 Outlaw with a 525 EFI. From what I have been reading it could be one of many sensors. He is going to have a local repair shop scan it and see what sensor is causing the problem .Sending the 3 beeps at about 1 minute . Hopefully and easy fix. Should know more this week once he gets it scanned.

Yes you are a wealth of information and I read lots of your posts. Nothing but respect from my end. lol I would not know what I know if it wasn't for guys like you.

Steve

My friend has not been able to get his boat in yet to get scanned. However after looking it over, he found that he forgot to hook up the cam sensor when he put it back together. He plugs it in and figures that was the problem. Now it won't start? Boat started and idled with it unplugged, but had the 3 beeps every minute.