1990 Isuzu pickup wont start

Hi all- This truck is pretty finicky in the cold weather but it has always started. Ok I took out the stereo in the truck to put into my Honda Accord and now I cant get it to start. There is an external fuel pump and the previous owner ran a white wire to the ignition and a red wire to the fuel pump circuit in the fuse panel. Now somehow I have a loose end like I need a ground wire for some reason. Do these wires need to be grounded? Or one of them? Seems to me the pump is on but maybe I need a ground to actually get the fuel moving. Help!!:disappoin:sunglasse