Tachometer rolling up by itself.

[gitu23]

Hi I m new to this forum and spend some time to find out my problem here.
I just have bought my explorer sport trac 2002 with electric problem concerning power windows driver and rear passenger not working. I was playing with master switch when realize that my speedometer arrow acting weird like go to 20mph and more and rolling my millage tachometer up. It happening with engine not running and ignition key are in ON position. Also if someone has electric diagram for all power windows circuit I will be appreciate. Any idea what and how this speedometer/tachometer roll up issue.

 

[swshawaii]

These trucks are known for strange behavior with faulty batteries or connections, especially gauges and lighting. Have it tested.

 

[gamikzone]

Do you hear any clicking when it does this, if my battery isnt fully connected my tachometer will get stuck.

 

[gitu23]

No any sound

no any sound or click but in deed battery are very weak and with old/rusty clamp.

 

[gitu23]

gamikzone You are right. Changed battery plus clamp and tachometer/speedometer works properly. Thank for the input.