I'll try one more time, no one ever seems to respond.
I have a 2007 Gr Cherokee & the tach is stuck on 1500 rpm. Car runs fine.
Any ideas? Thanks

 

Try giving it a hard whack from above the dash. Check the dashboard grounds and also clean the main dash ground in the engine compartment. It’s also possible the gauge cluster needs replacing or is corroded behind. Good luck

 

Thanks, but I have no idea where the main dash ground would be located.