My gas gauge always goes to full even if i have no gas. How can I fix this??? Also where is the sensor in the tank located and whats the easiest way to change it out with a new one?

Also, the needle for the temp jumps all the way past high on start up and I have to tap the needle to get it back to normal... Why does it do this? My cousin said that he put in a wrong car battery and it over regulates the system making it do that and causing the fuel gauge to go out of wack?>??

Please let me know what your thoughts are..
Thanks

 

Battery has nothing to do with it, as long as it's a 12v battery.

Sounds like you have a dash connection loose, maybe a ground.

 

Loose ground? Could u be a little more specific, not sure where to start looking.

 

Loose ground? Could u be a little more specific, not sure where to start looking.
I don't know much on electrical could u help a lil more plz