Thermostat senders vs sensor (pics attached)

[akamoonman]

Took boat out and right off the bat the overheating alarm buzzed. I know the boat wasnt overheating as i just started it.
Is there a difference from a water temp. sender vs a water temp. sensor.
My 5.7 mercruiser has a sender on the left side of the housing and a sensor on the right side of the housing. Difference after some research is the the sender (left side) is about 30.00 while the sensor (right side) is 130.00.
are they interchangeable? Do i need both?
thanks for any and all help.

John

 

[dingbat]

Difference after some research is the the sender (left side) is about 30.00 while the sensor (right side) is 130.00.
are they interchangeable? Do i need both?
thanks for any and all help.

John

A "sender" is typically an open/close switch used for status....aka over temp light

A "sensor" is typically a measuring device with an analog output of some scaling - aka water temp gauge

 

[Bondo]

Ayuh,..... Welcome Aboard John,..... I see ys figured out the picture thing,....

As dingbat says, no they're not the same,....
As for "Needing" either one,..??..??
Which ever one you put a pipe plug in, that system won't work,.....

If you put the sender in place of the sensor, the temp gauge will show nothing, til it pegs at an overheat situation,.....
If you put a sensor for the sender, the buzzer will groan all the time,......

 

[Bt Doctur]

there are 3 systems tied together for alarm. no engine oil pressure, high engine temp, low/no outdrive oil

 

[akamoonman]

Ayuh,..... Welcome Aboard John,..... I see ys figured out the picture thing,....

As dingbat says, no they're not the same,....
As for "Needing" either one,..??..??
Which ever one you put a pipe plug in, that system won't work,.....

If you put the sender in place of the sensor, the temp gauge will show nothing, til it pegs at an overheat situation,.....
If you put a sensor for the sender, the buzzer will groan all the time,......

Bondo.
Appreciate the feedback. it is helpful.