Engine/Transmission (1998.5 - 2002) Temp guage not working high idle issue

Started truck, high idle, noticed temp gauge not working. Replaced temp sensor unit, gauge still not work, still high idle. let truck sit few days, now no high idle issues and temp gauge is working properly. Is this issue going to occur again?
Is something causing issue other then temp sensor not working? What is best way to trouble shoot this issue? Thanks

 

It would help to know what truck you have. If you would put that information in your signature you wouldn't have to type it in all the time.

 

99 3/4ton, 24 valve 235,000 miles

 

Has battery acid overflow on the drivers side battery and screwed with the temp sensor under it? I believe that is the sensor that triggers high idle at below around 28 degrees if I remember correctly. SnoKing

 

Not think so. Water temp gauge was not working, when disconnecting water temperature sensor high idle stopped. Replaced water temperature sensor with oem sensor, water temperature gauge on dash still not work, still high idle. Let truck sit for few days and now water temperature gauge is working properly and no high idle issues. Not know if issue is fixed or will return.

 

Strange, the water temp is what turns off high idle at 175 degree. The temp sensor under the battery or intake temp is what kicks it in.

http://www.dodgeram.info/tsb/2001/18-019-01.htm

So I think you found how to turn it off, but not why it started.