2007 90hp 4stroke alarm goes on and off

need help alarm sounds on low allthe time after starting untill i reach under dash and wiggle the wiring harness after trailering boat it would not start untill wiggled wires under dash is it alarm or something else?

Not familiar with 4 stroke setup, but one would think if Merc did it one way on their 2 strokes then surely the 4 strokes would be the same. On my 2 stroke, there is a horn type device in the control box or in the wiring harness near it. It gets 12v on one side when the key is turned to on or start.

If it gets a ground on the other side it will sound. Ground comes from an over temp switch in the engine that closes at about 195F during an over temp comdition. It also could be caused by a low oil level in the oil tank. On some engines that is a solid alarm like the OT and others it is a broken beep beep.

If you are wiggling wires and having it come on then I'd suspect that you have an exposed bare wire touching a ground terminal somewhere. I would lie down on the floor beneath the dash and look and wiggle till I found the problem.


Mark

Thanks for the reply going to pull harness to try and locate problem

dave cat320c said:

Thanks for the reply going to pull harness to try and locate problem

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While doing that, physically grasp wiring lugs attached to terminals ensuring that they don't wiggle (loose). Sometimes, for closely mounted, non-insulated terminals, one can reach over and connect with an adjacent terminal lug causing problems.

Mark