My tach has a mind of it's own! Reads all over the place, even clear off the scale. If I disconnect the battery for a few minutes, it will work fine for an indefinite amount of time and then suddenly act up again. Any thoughts?

 

is it a v6 or a 4-cylinder.
has the tach ever been replaced or removed for any reason?
Have you ever changed the distributor? If you are using a magneto distributor, you must have supression core spark plug wires, silly i know.

 

I believe it's been over 10 years since any vehicle rolled off the assembly line with a working distributor (Dodge Ram truck 5.9L); 20 years ago if you narrow it down to the Chevy 60-degree V6 (2.8/3.1/3.4L/3100/3400). The 3400 V6 was the only engine used in the 2007 Equinox and it has a distributorless ignition system like virtually all other modern vehicles.

 

Try pulling the fuse for the gauge cluster. I have an 07 as well and my fuel gauge went nuts a while back. Pulling the fuse seemed to work for me.

 

Will most likely need to replace the motor in the cluster for the tach, you can by them on line. They come as a kit with motors(servos) and replacement led lights.

 

Lol didn't think about that one. I still drive an old chevy with one. Lol