check the drive fluid, happened to me a week ago.

Wow...I stand corrected. I am not shocked that the controller has a provisional for a sensor/alarm input, I am shocked that merc would upgrade the HP and not the MAG as the controllers/features are virtually identical. Like I said earlier, to the best of my knowledge, the MAG502 AWS was completly contained within the engine wiring harness...I was assuming the HP would be the same. Have a good day.

Mag502num,
No worries, the HP500 EFI is a unique animal unto itself. Sorry I was so abrupt earlier, I am simply tired of so call Experts or Master Certified Technicians who claim to know "moore" on but in reality know dick.
Good Luck

Again, thanks guys for all the impute. Always great information on here.

The drive fluid bottles were full, or so my buddy says.... As were all fluid levels.

I'm surprised that low fuel pressure is not part of the warning system. With as much damage that can happen from low fuel pressure, it's surprising.

Well, it appears that I was also wrong about the 502 mag audio warning system....it is also NOT a stand alone system. I just checked the plug where the engine wiring harness plugs into the ecm harness and plain as day there was tan/blue AWS wire!!!! Learn somthing new everyday. Adivanman, thanks for setting us[me] straight. Also, I didnt take your post personal at all. Thanks for the info.

Theres a real easy test for the drive bottle sensors. UNPLUG EM. If the alarm stops,fix the sensor.

I've had a couple of oil pressure
switches fail.
Do the same as Air Packer mentioned
with the drive bottle sensor,...Unplug it,
see what happens.

jt

Air.......he unplugged them, & the alarm still went off. He put the boat in a whse out of state due to the storm we had down here, so the trbl has not been re-visited for a couple weeks.

Thanks for the info......

That being the case,one by one unplug the sensors for oil pressure ,over heat etc and see if the alarm stops. The o/p switches can fail closing the circuit to ground even with good oil pressure.

Hello,

Not sure what is causing your alarm, but for those that dont know me.. My name is Dick.

Alarm circuits in general will take the alarm buss to ground, a short can cause it as well as a sensor. If the computer is involved all bets are off.
Any input as to why it idles at 1200 rpm after the alarm goes off. Programing trying to cool off a supposid hot motor maybe..?? Just guessing here, but it seem like there are some clues here that might mean something. I dont know what, but someone (computer programer) might.

Oh by the way no offense taken on the dick comment, been named Dick too long to care.. LOL

Dick