Stuck temp gauge

[RubberDuck]

I think I already know the answer to this, but figured I'd ask anyways. It appears my temp gauge is "stuck" whether the jeep is on or off. At first I was afraid the jeep was overheating because it was pegged fairly high. But it is in fact stuck. Due to some rather questionable modifications the PO did to the dash (he mounted a factory tach too high on the dash so then cut the windshield thumb screw in a round contour to go around it???) It seems like it will be a nightmare to get the dash off to replace. I honestly don't even know how he got the thing on. Is there any way to "shock" the thing loose for lack of a better description? Perhaps shorting the sender?

 

[barrys]

You can remove the cluster without taking the dash off. It's a pain but certainly doable.

 

[Spieg]

I believe those meters are pegged when grounded. I'm assuming it stays the same whether the ignition is on or off? You could try removing the wire from sending unit and quickly touch it to ground and see if it knocks the needle loose, but I doubt it will help in this case since it's already stuck in pegged position case.

 

[RubberDuck]

You can remove the cluster without taking the dash off. It's a pain but certainly doable.

I assume I’d need to get to the back of it to get the cluster out. There’s an aftermarket AC there as well so that’s probably out. I need to take a picture of this very precisely executed Jerry Rig the PO did to the windshield nuts. I honestly have no clue how he did this.