overheat alarm not working. 1990 johnson 140hp

[bparks1]

hooty and friends,<br /><br />When I had the rebuilt Johnson 140 (1990) checked out (buying boat), the mechanic said the overheat alarm on the temp gauge was not working. Any ideas? It's on a 1990 18' Searay bowrider with all gauges in console.<br /><br />j140

 

[bparks1]

Re: overheat alarm not working. 1990 johnson 140hp

hooty and friends,<br /><br />Forgot this! <br />The "auto oil mix" unit is bypassed. I mix it 50:1 manually. Maybe this will help.<br /><br />When I had the rebuilt Johnson 140 (1990) checked out (buying boat), the mechanic said the overheat alarm on the motor temp gauge was not working. Any ideas? It's on a 1990 18' Searay bowrider with all gauges in console.<br /><br />j140

 

[almost retired again]

Re: overheat alarm not working. 1990 johnson 140hp

Is the tan wire from the temp sending unit still hooked up? If so ground it, the alarm should sound off,if it don't I would suspect a bad connection or broken wire somewhere between it and the warning horn. Maybe even a bad horn.

 

[bparks1]

Re: overheat alarm not working. 1990 johnson 140hp

thanks ahead.<br />yes we grounded it and no sound. I'll check the continuity to the alarm. Is that the small disc shaped plastic device free hanging in the wire harness under the console?<br /><br />just in case what is a safe operating temp on the gauge? 145'Farenheit to 165' F