The fuel gauge in my El Camino suddenly reads full. I know it's not full. Driving around doesn't change it. Is this a ground issue, a short, or open circuit? Where should I look?

Thanks

the sending unit is the ground ... so opening the circut will lower the guage .. it posible you've grounded out the sending wire if the guage is reading full all the time & its not.......

XNY89, Check the ground wire coming off the fuel sendor going to the frame/body(black wire).Seen it many times, the ground on the body goes bad. graemlins/thumbsup.gif

If it is reading past full then you have an open circuit. Ground or 0 ohms is empty.
Go here for a complete troubleshooting guide for fuel gauges.
http://www.chevelles.com/techref/ftecref18.html

OPPS graemlins/clonk.gif my post was not correct... it should have said emtpy.... (note to self don't type anything till coffee kicks in)