Temp gauge says overheating but the truck is 195°

[80C20Jon]

Hello everyone , looking for advice, My temp gauge slowly goes up all the way to hot. truck is running at 195. Tried a new temp sensor same , 2 other gauges same , different printed circuit same , wired completely separate same. Making me think I need another new temp sensor have ordered one

 

[SquareRoot]

How do you know it's running at 195?

 

[80C20Jon]

How do you know it's running at 195?

Yes , checking with laser temp gun

 

[SquareRoot]

Yes , checking with laser temp gun

Your measuring surface temp assuming it's accurate. So, you have replaced every part of the gauge circuit and still have the same result based on the laser gun reading? Is the sending unit the correct one for the application?

 

[nvrenuf]

I’d buy an aftermarket mechanical temp gauge to double check the factory gauge.

 

[80C20Jon]

Your measuring surface temp assuming it's accurate. So, you have replaced every part of the gauge circuit and still have the same result based on the laser gun reading? Is the sending unit the correct one for the application?

I'm looking into that , there is a 3/8" and 1/2" sensor, my block is a 1/2" hole. Is there different 1/2" sensors? My laser temp gun is accurate

Your measuring surface temp assuming it's accurate. So, you have replaced every part of the gauge circuit and still have the same result based on the laser gun reading? Is the sending unit the correct one for the application?

Getting parts at O'Reilly's only 2 options. If the 1/2" one I ordered does the same I'll get the 3/8" one and use a bushing to put it in the 1/2" hole in the block. My temp gun is accurate I tested it.

 

[75gmck25]

Exactly which sensor did you buy? The sensor resistance profile changed over the years, and usually the one the parts guy pulls up for older trucks is not correct.

It took me a while to find one that worked well with my ‘75, and it’s got the correct 1/2” threads. The TS6T has the nailhead connector used on my ‘75, and it reads correctly. TS6 has same profile, but a different connector.

 

[80C20Jon]

Exactly which sensor did you buy? The sensor resistance profile changed over the years, and usually the one the parts guy pulls up for older trucks is not correct.

It took me a while to find one that worked well with my ‘75, and it’s got the correct 1/2” threads. The TS6T has the nailhead connector used on my ‘75, and it reads correctly. TS6 has same profile, but a different connector.

Thank you I will look at my receipt