My temperature guage in my van quit working!

Discussion in 'Shop Talk' started by r.h. in okla., Jan 1, 2005.

  1. Plenty of water in radiator. Heater works. We had a cold spell a couple of weeks ago and that is when I first noticed something wasn't right about it. During the cold spell the guage would come up to normal and then a few minutes later it would go back down to zero. I first thought maybe it was so cold out that it was keeping the engine cool but now we are in our 60's and it doesn't rise at all now. Any suggestions on what might be causing it?
  2. Forgot to add it is a 97 dodge caravan.

  3. moopups

    moopups In Remembrance

    May 12, 2002
    In beautiful downtown Sticks, near Belleview, Fl.
    Check the sending unit for grime, replace the sending unit, replace the gague, after that ask again if it does not work. Check the wires also. It ca be either or all of the above things.
  4. Beeman

    Beeman Well-Known Member

    Dec 28, 2002
    East TN
    The sending unit for the gauge is a rheostat. As the temp of the engine changes the resistance of the sending unit changes which makes the gauge move. Now for the bad part. That year Caravan probably has a body computer beside having a drivetrain computer. This is all from memory as it's late and I'm not in the shop, but the dash is possibly controlled by the body computer. Try unplugging the temp sensor, be sure you unplug the right sensor, and run the engine and see if the gauge moves. If the gauge changes with the sensor unplugged you probably have a bad sensor.