Tachometer drops to 0

[Sphinx]

For some reason, randomly my tach will drop down to 0... Car idles normally... and when I start to accelerate it will go back to normal.... Any ideas?

[screamn]

Sounds like a loose wire maybe a ground issue.

Or worse Tach gauge is going bad/failing

[Ken]

The tach as well as the speedometer kept dropping to zero, when the alternator went bad on my F150.

[ctrlraven]

Start with checking grounds.

[fastblackmerc]

Start with checking grounds.

Especially the grounds in the engine compartment.

[boatmangc]

Mines been doing that for 3 years
Went through the grounds
Pulled the cluster, connections were clean, guessing its my tach
It doesn't appear to be a modular component
I figure one day it'll die completely and I'll deal with it

[whitey]

mines been doing it for a couple months. ctrlraven looked at my grounds briefly, nothing was found, and i took apart/out the entire gauge cluster hoping to find a loose wire....but again, nothing was found. cleaned everything up with electrical cleaner spray, even a small file, and TADA!!!!...to my dismay it still fluctuates. atleast i tried:(.