Fuel tank, fuel sender ground?

[JGB]

'85 Cig 20. I replaced the fuel sender but there wasn't a black ground wire available to ground the sender. I reached in to feel around for a loose ground wire to connect but couldn't find any loose wires. I did notice the sending wire was running together with a thicker black wire( which was firmly connected to something on either end. I am wondering if the thick black wire grounds the entire fuel tank and thus eliminates the need to ground on the fuel sender's grounding jack? (because there is a staple in the fuel sender gasket that allows for metal to metal contact between the tank and the sender) Any ideas whether I still need to ground the fuel sender what is the best way to run the wire to ground it? Seems as though the fuel tank area is totally enclosed.

Thanks for any help.

Jim


BTW, I'm getting real close to be able to splash her. But would like to put myself at ease by getting this ground issue resolved.