Temperature Gauge Stuck on Hot

[paintlikeaking]

I have a '97 Mazda B2300 and a few days ago the temp gauge is stuck past hot and is on the verge of touching the RPM gauge. I drove the truck that morning and everything was fine. I parked the truck for several hours and when I came back the gauge was stuck yet the engine was cold. I replaced the Temp sending unit with an ORielys replacement which didn't fix the issue. I also pulled the cluster to see if maybe the needle was stuck but that also failed. When I disconnect the sending unit the needle freely moves but as soon as it is reconnected it skyrockets again. Please help this is my daily driver.

 

[ratdude747]

I have a '97 Mazda B2300 and a few days ago the temp gauge is stuck past hot and is on the verge of touching the RPM gauge. I drove the truck that morning and everything was fine. I parked the truck for several hours and when I came back the gauge was stuck yet the engine was cold. I replaced the Temp sending unit with an ORielys replacement which didn't fix the issue. I also pulled the cluster to see if maybe the needle was stuck but that also failed. When I disconnect the sending unit the needle freely moves but as soon as it is reconnected it skyrockets again. Please help this is my daily driver.

Check your dash connections and cables. Schematics available here:

http://www.therangerstation.com/forums/showthread.php?t=165475

There's two sides of the needle in the cluster. If the non-sensor side looses power, it will jump to the high side like that. I had this happen with my (modded) oil gauge when I had one of the connectors unplugged; these type gauges have one coil which is driven by the sensor, and another that is driven by a fixed supply (battery voltage and a resistor).

Also check the needle's connection to the plastic "circuit board" (if you want to call it that, it's thin plastic film) as that would also do it.

So you either have a split wire, bad connection, or (least likely) bad temp needle.

 

[paintlikeaking]

Check your dash connections and cables. Schematics available here:

http://www.therangerstation.com/forums/showthread.php?t=165475

There's two sides of the needle in the cluster. If the non-sensor side looses power, it will jump to the high side like that. I had this happen with my (modded) oil gauge when I had one of the connectors unplugged; these type gauges have one coil which is driven by the sensor, and another that is driven by a fixed supply (battery voltage and a resistor).

Also check the needle's connection to the plastic "circuit board" (if you want to call it that, it's thin plastic film) as that would also do it.

So you either have a split wire, bad connection, or (least likely) bad temp needle.

Thanks for this. I'll try that when I get off work and see if that helps anything. I appreciate it!