Mezmorized
Member
Unless there is more than one temp sensor... it's not the sensor cuz as soon as I unplug it, the rpm's change. Is there a place I can mount a mechanical gauge probe?
-
Welcome to The Truck Stop! We see you haven't REGISTERED yet.
Your truck knowledge is missing!
- Registration is FREE , all we need is your birthday and email. (We don't share ANY data with ANYONE)
- We have tons of knowledge here for your diesel truck!
- Post your own topics and reply to existing threads to help others out!
- NO ADS! The site is fully functional and ad free!
Problems registering? Click here to contact us!
Already registered, but need a PASSWORD RESET? CLICK HERE TO RESET YOUR PASSWORD!
Temp gauge is bouncing all over the place...
- Thread starter Mezmorized
- Start date
- Staff
- #2
The sensor in the t-stat housing is for the ECM, the one for the gauge is in the drivers side cylinder head.
Will L.
Well-Known Member
If not bad sensor,(the other one you were not unplugging) check harness connection ends.
My rule (adapted from many fleets doing this) says: time and corrosion that ruined 1 sensor is soon to kill the other, so change them both at same time (and possibly flush) before refilling cooling system.
My rule (adapted from many fleets doing this) says: time and corrosion that ruined 1 sensor is soon to kill the other, so change them both at same time (and possibly flush) before refilling cooling system.
Mezmorized
Member
I'll look for the sensor on the drivers side cylinder head. 
JayTheCPA
Well-Known Member
Ah, suspected as much. This explains why my Edge and dash gauge do not track evenly with each other until the engine gets warm.
ghitch75
livin' in the sticks
check and clean your grounds.......
Mezmorized
Member
Someone refresh my memory, what do I do to test the sensor? Do I just check it for shorting to ground?
Temp sensors usually have a resistance/temperature chart to measure and compare. It can be different than the dash sensor chart.
Also: do a wiggle test on wiring. Inspect for corrosion as this changes the resistance and readings like crazy with any present. Replace the connector and sensor if there is any corrosion because it is too sensitive to try and clean. (Low voltage low current with little resistance changes meaning a lot is why this is so sensitive.) Short to ground is a valid test on 2 wire sensors. Test ground from the body to engine via voltage with engine running. The sensor can get hot and then short to ground.
Also: do a wiggle test on wiring. Inspect for corrosion as this changes the resistance and readings like crazy with any present. Replace the connector and sensor if there is any corrosion because it is too sensitive to try and clean. (Low voltage low current with little resistance changes meaning a lot is why this is so sensitive.) Short to ground is a valid test on 2 wire sensors. Test ground from the body to engine via voltage with engine running. The sensor can get hot and then short to ground.