Gauge cluster not working

[TheClev.z71]

My friend has a 96 rc stepside and his oil and temp work. His gas gauge works opposite of normal. He gains gas as he drives but not that big of a deal. But his speedometer is about 20 mph fast an tachometer stays maxed. I took it out cleaned and put it back in. Any suggestions?

 

[DRAGGIN95]

I would use a live data scanner and view the live data stream first to see if the ecm is reading correctly before going any further.

 

[Horns]

It would also be a good thing to check the grounds.

-Sent from my twin turbo Desire using diesel fuel.-