[oldeflyer]

Digging with my 2021 TLB 2025r this week. Outside temps were in the 90s.
I noticed that the temperature gauge on the dash never moved off the low peg.
Never really noticed the gauge being pegged low since all my tractoring until now has been in cold weather.
Looked under the hood and have NO idea where anything is. Frustrating since I used to rebuild small block Chevy engines.
I think the attached photo is the temp sensor.
I found an unattached wire (other photo) over on the other side by the exhaust expansion chamber?

Does the wire go to the assumed temperature sensor? If so, it has never been hooked up:-(

Thanks for any help,
Wayne

 

[kylew]

Yes, that's the coolant temp sensor, in the t-stat housing. The wire probably belongs there. It does use that type of connector, and the only other sensor that uses that type connector is the oil pressure switch, but that's half way down the right hand side of the block, rear of center.

Does the wire reach the coolant sensor? Plug it in and try it, you won't hurt anything. The coolant sensor is a variable resistor, so you should see the needle start to move after a couple minutes. Doesn't take long, especially if you're higher than idle.

P.S. The 'exhaust expansion chamber' is the muffler. Lol

 

[oldeflyer]

Kyle,
Thanks for the reply. I thought that that wire was it but I didn't want to just plug it in in case might screw something up.
I did find the oil sensor electrical connection. It looked like what it was supposed to be.
As far as the 'exhaust expansion chamber', I know bubcus about diesels so I wasn't sure what it was (didn't have any exhaust pipe clamps that I could see). Thought the thing had a straight pipe as loud as it is.
I'll give it a go tomorrow. First time I really looked under the hood, except for connecting the battery saver.
Thanks,
Wayne

 

[jsb2b]

At all outside temps, winter and summer, my temp gauge needle will be about 1/8" off the peg. Even with the grille being covered with debris. Measure the temp of the top of your radiator. If it's around 140 degrees, your sensor is bad.

 

[oldeflyer]

Update:
Temp sensor apparently never hooked up. The wire as situated would not reach.
A little reroute up and over by the oil fill cap and it just reaches. And goes on with some difficulty.
Low eighties outside and back to pond mucking. Temp gauge needle does move now but as jsb said only about an eighth to a quarter of an inch.
I do have an infrared heat sensor for my model helicopter motors. I will look at the radiator temp using that during tomorrows pond mucking.

 

[kylew]

Temp gauge needle does move now but as jsb said only about an eighth to a quarter of an inch.

That's about normal for the stock 160° thermostat. I have a 180° in mine, and it goes just a tad higher than it did with the 160.

 

[oldeflyer]

Okay,
Back in the pond again and popped the hood and used the infrared handheld on the radiator as I was finishing up. 140 degrees F w/88 degrees outside temp. Ran the RPMs at about 3000 for the digging.
Guess the gauge is working now.

 

[CityBoyBG]

Okay,
Back in the pond again and popped the hood and used the infrared handheld on the radiator as I was finishing up. 140 degrees F w/88 degrees outside temp. Ran the RPMs at about 3000 for the digging.
Guess the gauge is working now.

My gauge needle has never been past 1/4-3/8" of movement over the last year of 130 hours of hard work for my 2019 2025R.

Put another way, it also strikes me as never having moved more than about a quarter/third (at most) of the range implied by the gauge. Ground work, backhoe, heavy mowing over two summer seasons in very hot conditions, winter plowing with big blower, etc.

So, your new situation matches up roughly with mine, for what that is worth. Good repair. Enjoy.