1977 evinrude

[smithbader]

I bought a nice used pontoon boat the other day with a 1977 evinrude 85hp. When I started it today the overheat alarm sounded so I shut it down....now as soon as I turn the key the alarm sounds without motor running... don't understand it.... very clean motor but I know it's gots some age on it. Anyways any idea why this is happening

 

[interalian]

It may have actually overheated and the sensor stuck closed. There's one on each head. Disconnect the brown wire (under the black rubber sleeve, knife connector) and see if the alarm stops. If you disconnect both and the alarm still sounds, look for shorts in the wiring harness.

It's also possible it didn't overheat and just one of the sensors failed short or wiring got shorted.

When was the water pump impeller replaced last?

 

[smithbader]

Supposed to have been less than 2 years ago, new one going in this week

 

[interalian]

Two years is probably fine. How about the other questions?

 

[smithbader]

Update... replaced water pump looked OK. Old water pump looked fine. Put all back together and when I turned key alarm still sounded, even disconnected wires on the motor same results. Took apart shifter as best I could and removed the small black alarm horn. It has 3 wires that connects... disconnected all taped up connecters shoved it all back in and all is well

 

[flyingscott]

But now you don't have an overheat warning I would find the problem and fix it.

 

[gm280]

I have to totally agree with flyingscott. You didn't fix anything. You simply removed the audio report alarm section and now have no idea if your engine ever gets too hot. I would fix the real problem and then boat happily on. Just just removed a nice option from your engine.

 

[smithbader]

I agree with both of y'all so I'm trying to replace this alarm/buzzer but so far no luck finding it

 

[interalian]

If the buzzer sounds, it's fine and does not need replacing. If it's sounding with both leads from the thermal switches disconnected, you have a short to ground somewhere in the wiring harness. Most likely place is somewhere the cable bundle flexes most, or is clamped, such as the cable exit at the front of the motor.