Tach jumps and sometimes sticks

[Bryan E 2]

Wondering if anyone has insight into this issue. The Tach will sometimes jump up to 4,000 RPM (motor is at idle) then while driving it will jump around also, it never jumps below the current RPM. The motor doesn't increase RPM just the tach. If I tap the dash it will return to where it should but then usually goes right back to jumping around.

 

[Craig Martin 2]

Sounds like something is loose on the back of the cluster. My gas gauge isn't reading correct and I think it might be a loose connection. Just haven't tried pulling the dash out just yet.

 

[Yardsale]

This doesn't seem like a loose ground. If it were, I expect the tach to stop (go to zero). This seems like a short to hot. Maybe a bad solder joint, failing resister or sensor causing a spike.



Yer gonna have to open 'er up.

 

[Craig Martin 2]

Yeah thats's what I was thinking Yardsale but it just didn't come across that way lol. By loose connection I meant loose/bad solder joint.