Once in a while my speedo dies and sits at zero. Started happening on left turns but now its dead all together.

I checked the connector at the rear of the tranny. Its snug.

What else would cause this?

I have a 93 with a 700R4.

 

ttt

 

maybe your VSS?

I would say first try someone elses cluster and see if it works, if not, try replacing your VSS.

 

Does it come back alive after you smack the dash?
Mine does it when my car sits in the sun for a while, if I smack the dash it comes back alive

 

Here is my opinion, was a service advisor for 8 years at a Pontiac dealership, vehicle speed sensor on transmission rarely failed, almost never. Instrument cluster problem not common but usually the culprit. Anything can happen just wanted to state my past experience.

 

Ok here's what happens...

When I first start the car the speedo is dead. As I drive or when the tranny shifts into overdrive at 45mph, it comes back.

Sometimes dies on left turns.

Usually after the car has been running for an hour its fine.

 

My one T/A just did it to me today. Its around 88 degrees out here so I smacked the dash and everything worked again.

 

Mine doesn't come on when you tap the dash.

Comes on when the car is warmed up.