Fuel gauge

the fuel gauge in my 99 astro does not work. It reads full most of the time but occasionally will drop suddenly to empty. Could the problem be external to the tank like the gauge itself or some other sensor?

Possibly in the wire that connects to the gauge, but more than likely a bad sending unit in the gas tank.

I concur. Sending unit. (I believe it’s in the tank) $200+ CDN.