alarm does not go off

[LANCETHOMAS]

I have a 79 evinrude 175 and the alarm stays on anytime the key is on or motor is running. Is it supposed to be on when you first turn the key on and then go off when it starts? Engine is fresh rebuild and runs good and is not overheating.

 

[emdsapmgr]

Re: alarm does not go off

You should not hear any horn till that engine overheats (212 degrees.) Much later models will beep the horn once each time the key is switched to on-as a horn test only. If you have a constant horn, you have a problem with the wiring for the temp switches in each head. You may have a dead short to ground with the brown wire, or one of the two switches is faulty. I'd disconnect one temp switch individually at the knife connector at the head. See what happens, then reconnect and disconnect the other. The switches activate by going to ground when they reach 212.

 

[LANCETHOMAS]

Re: alarm does not go off

Thanks, thats what i was thinking. How do you get the temp. sensors out of the head to replace them. They look like they are just pushed in a rubber gromet.

 

[boobie]

Re: alarm does not go off

They are held in by the cyl head COVER. You will have to remove the cover to remove the temp sensors. Probably have to replace the cover gaskets also. Make sure one or both is bad before replacing.

 

[HighTrim]

Re: alarm does not go off

Have you first tried disconnecting the tan wire to your horn? If is is still sounding, the horn is your culprit.

 

[LANCETHOMAS]

Re: alarm does not go off

I am going to disconnect the temp wires one at a time to try and figure out which one or both is bad. Is there only one tan wire in the control box plug?

 

[boobie]

Re: alarm does not go off

Yes, It splits in the mtr wiring harness going to each cyl bank.