Head temp sensor ?

jimwolcott

Recruit
Joined
Jun 22, 2008
Messages
2
I have a 2000 35hp 3 cylinder Johnson, i have replaced my head temp
sensor two times in the last 2 months. After one over heat alarm the
switch seems to not reset itself, it stays in a constant alarm condition.
It will cause the alarm even after sitting on the trailer overnight when
every thing is stone cold. At $80 a pop this is not right. Is there some
way to reset them or am i just getting bad ones right out of the package.

I have a brand new water pump, complete new thermostat housing etc.
The motor runs fine with the switch disconnected, cool engine, good
water flow from the telltale.
Thanks, Jim
 

clanton

Rear Admiral
Joined
Jul 9, 2001
Messages
4,876
Re: Head temp sensor ?

The horn is the problem, not the sensor.
 

jimwolcott

Recruit
Joined
Jun 22, 2008
Messages
2
Re: Head temp sensor ?

The 2000 35 hp motor has the system check that checks 4 functions.
All the other self tests work fine, it runs thru all the tests. Beeps at
each funtion then shuts off. The whole wire harness, horn and system
check are only a couple months old.
With the head temp switch connected the motor goes into limp mode.
With it disconnected it runs normall, temps are cool. This is the second
time it has done it, both times with new switches.
Jim
 

clanton

Rear Admiral
Joined
Jul 9, 2001
Messages
4,876
Re: Head temp sensor ?

You checking the temp sensor with hot water and meter. open when cold,closed when hot. If the 2 sensors are bad, take back to dealer for warntty. Tan wire to sensor is ground only, check for voltage. I need a wiring diagram, don`t have. The senors wires are all tan with a colored stripe to id the wire. Sensors should be temp, low oil, not sure about no oil. The sensors wires go to a tach or the small gauge with 4 red lights. 2 wires from tach/small gauge to horn. The tach/gauge has the logic to work the horn. If you just installed this sysem the tach/gauge is bad, system wired wrong, wrong horn. You have time list all wire colors and connections. you want to call 850 319 9663.
 
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