Fuel pump wired wrong? Low fuel gauge
 

This is on a 2000 4dr blazer. (P0463) I have searched and searched and the wiring doesn't seem right. When I bought this blazer the gauge didn't work . It has always been on low fuel. The purple and black wire both read 12v+. Pictures i have seen have the wires swapped.
the purple wire coming off of the pcm has the proper 5v reference.
I replaced the pump after purchase thinking it was just a bad sending unit. Wired it up exactly like they had. Thanks for any and all help!!!
https://cimg8.ibsrv.net/gimg/blazerf...8e0a0ff38f.jpg


https://cimg0.ibsrv.net/gimg/blazerf...90476afa48.jpg