Temp Gauge/Switch

[TX Duck Guy]

I pulled the head cover last night (1963 Evinrude 40hp) and found what must be the temp sending unit. It is in the lower left of the water passage cover and has a single wire coming out of it. Maybe it's a thermocouple or something that changes its resistance as temp increases. The wire isn't hooked to anything at this time. Can someone explain the function of this unit? Does it drive a gauge, buzzer or is it a kill switch? It seems like an important piece to have working, so is there any test procedure? <br />Thanks!

 

[Droll]

Re: Temp Gauge/Switch

Temp switch :<br />When overheating > switch activates ( wire connects to ground ).<br />You connects a horn directly to +12v and the other connecting thru this switch = overheat alarm.<br />To test :when cold > switch open ,overheated = switch closed .<br />Test alarm > short wire from switch to ground = horn sounds .

 

[TX Duck Guy]

Re: Temp Gauge/Switch

Thank You! That's what I needed to know!