Temp gauge

[1994xlt]

Hello yall as you may know I had a motor put in my truck a few weeks Ago and this week I noticed my temp gauge won’t work right, the heat blows hot and stuff but the gauge never gets to the normal Range? The thermostate is new so it shouldn’t be that but I guess it could, but went I’m like on it an accelerating the needle goes down significantly then it might creep up after a bit again but then go back down again after driving at a steady mph for a bit. I went to o Riley’s but think I got the wrong part I got a temp sender but I think I needed a temp sensor?

 

[franklin2]

That should be the right one. The older trucks had two. The single terminal one is for the dash gauge, the one with two terminals is for the ECM.

 

[1994xlt]

That should be the right one. The older trucks had two. The single terminal one is for the dash gauge, the one with two terminals is for the ECM.

Well now I’m curious what goes bad in these? There literally a stud

 

[SenorNoob]

They can really only go open or short. They just provide resistance to ground. The resistance changes with temperature to make the gauge move. You can force the gauge to one direction by grounding the wire. I think there is actually a chart floating round the 'net of resistance relative to temperature somewhere.

IMO, it sounds like you have air in your cooling system or voltage to the gauge is varying significantly. The gauge will vary with voltage. If you're sure you have all the air out I'd probably rig a voltmeter up to the lighter socket and see if the voltage matches the gauge dips. It'll probably be inverted. As voltage goes up the gauge goes down.

 

[ranger man'02]

im guessing something is connected poorly

 

[1994xlt]

im guessing something is connected poorly

Well I ended up getting the part so I guess I’m gonna dig into it today I gotta change my oil and stuff anyway

 

[1994xlt]

They can really only go open or short. They just provide resistance to ground. The resistance changes with temperature to make the gauge move. You can force the gauge to one direction by grounding the wire. I think there is actually a chart floating round the 'net of resistance relative to temperature somewhere.

IMO, it sounds like you have air in your cooling system or voltage to the gauge is varying significantly. The gauge will vary with voltage. If you're sure you have all the air out I'd probably rig a voltmeter up to the lighter socket and see if the voltage matches the gauge dips. It'll probably be inverted. As voltage goes up the gauge goes down.

To ground the wire do I just stick metal in it or what

 

[1994xlt]

im guessing something is connected poorly

here’s the new sensor I read somewhere teflon being on it is bad but it came on it

 

[ranger man'02]

well i can see why they would say that it would kind of insulate it from the block but whenever you screw it down its going to make a good connection

 

[1994xlt]

well i can see why they would say that it would kind of insulate it from the block but whenever you screw it down its going to make a good connection

Sorry, I’m kinda of confused what your saying

 

[ranger man'02]

Sorry, I’m kinda of confused what your saying

teflon causing a bad ground is why i think they say not to use it

but i think it would just, for lack of a better word, "bite through the teflon"

 

[1994xlt]

teflon causing a bad ground is why i think they say not to use it

but i think it would just, for lack of a better word, "bite through the teflon"

Ah ok