I hate my gas gauge

The temp and gas gauges on my 65 mustang quit working. I replaced the constant voltage regulator and it worked for about a day then the needle started swinging erratically before dying completely. I thought maybe this might just be because it was a cheap reproduction cvr so I replaced it with an original one and same result only this time it smoked a little before dying. I cant find a short circuit anywhere. Anyone else had this happen? Any ideas?

Check your ground cable. My '69 Cougar was doing all kinds of crazy shit. Turned out he neg battery cable which looked fine on the outside was corroded on the inside.