75 HP warning horn

[Rabbitdawghunter]

I've got a 75 HP Mariner Ser#OB249778. Owner said warning horn came on immediately after hitting big wake. What is the service manual part number, Mercury parts express does not list a service manual. Mastertech says that Mercury/Mariner manuals have gone up to 76.00 as of 2/1/2005? Everything looks good on the oil injection plumbing, no leaks or hoses off. I will run on premix to verify oil delivery and then start troubleshooting the warning system. Does this model use the lube alert module and if so what is the procedure for troubleshooting it.

 

[arboatdr]

Re: 75 HP warning horn

Was it a solid blow or intermintant beep? If it went off when he hit a wave I'd start looking at the oil tank. Verify the tank sensor is working if intermintant beep. The oil modules on this engine have failed on occasion. Unplug the blue wires from the oil tank to the warning module, if the horn continues an intermintant beep the replace the module. If the horn quits it's the sensor or the tank. If it's a solid blow check the brown temp sender wire coming from the back of the block by unhooking it. If the horn quits verify temp is within range and replace the sensor.

 

[Rabbitdawghunter]

Re: 75 HP warning horn

The warning horn is solid, but very faint, is that normal for this model? Grounding the brown temp sender wire makes the horn slightly louder and sometimes emits a grouling sound like a geiger counter (hope I spelled that right). Horn continues after the blue wires are unplugged. The horn I don't think would be audible above the running engine, of course my wife says I'm nearly deaf (or just have selective hearing)

 

[arboatdr]

Re: 75 HP warning horn

Did the horn go off when you unhooked the brown temp sender wire? If it did not sound while unhooked you have a bad sender(temp). If the horn continues to sound with the brown wire unhooked the horn itself is bad.

 

[Rabbitdawghunter]

Re: 75 HP warning horn

I removed the horn, after I disconnected it and reconnected it got much louder but still blows constantly, with the brown wire to temp sender disconnected.

 

[Rabbitdawghunter]

Re: 75 HP warning horn

Does anyone know where I can lookup the horn part number online. Mercury parts express does not list anything for the remote controls that I can find?