checking overheat alarm

[gator79]

how do you check the overheat warning system on a 1989 130 hp Yamaha?<br />thanks

 

[Jammu]

Re: checking overheat alarm

Disconnect the pink and the black wire from the thermoswitch, and connect the pink and the black from the harness, and if it's OK you can hear the buzzer sound from the control box. <br />Test the other side too.<br />If this is OK you can take out the switches and warm up them to test them that they are OK.<br />If the buzzer comes on they are OK.

 

[rodbolt]

Re: checking overheat alarm

hello<br /> to test the switches. remove them and place them in a pot of water. do not let them touch the bottom of the pan I suspend mine on a string. heat the water to about 185-195 degrees F.or 84-90 C. keep the ohm meter connected to the pink and black leads. use a candy thermometer to track water temp. the switches should close in that temp range and open in the 140-165 degree range. short the pink and black engine wires together with the key switch on to test the over heat alarm circuits. if this engine is oil injected now will be a perfect time to test the alarms for the tank and the oil transfer rate as well.<br /> good luck and keep posting