Ground problem?
 

Okay guys I really need help trying to figure out what’s wrong with my truck when I drive it my check Engine light gen light wait to start light trans temp light and water in fuel light all flicker really fast and speedometer quit working and my rpms bounce up and down its make my truck shift weird and drive weird and I don’t know where to start if any could help me that would awesome

Clean all ground connections. There are several. Oh and battery connections. Then clean. if possible all electrical connectors, then add some di-electric grease to connectors to help prevent corrosion. A bad connection or bad ground will raise havoc. Good Luck!

Okay so I figured it out it was a wiring harness hitting my driveshaft but my speedometer still isn’t working and nether is my odometer