I got a 1990 mustang gt and just stop running on my way to work I tought it was the fuel pump but I recently replace it, but I went to buy a new one anyway and nothing the car still not run i took the fuel pump out and I check if it was power on the connector to the fuel pump with a led and every time I open the ignition switch it lights but you can barely see it on I replace the relays on the car and nothing could some one advice me on what it could be wrong with my car thanks !  

So are you getting fuel pumped or not?
If you are, check the ignition coil.  If you are not sure how, let me know.
Good luck!  

not getting fuel pumped  

Theres no easy answer anyone here can give ya.  Check for voltage.  you should have at least 13 with full batt charge, if say there is only 8 @ pump, then trace the wires till next intersection , plug, relay, etc & check voltage if it goes up to batt then you have isolated the section of wire your short is in.  It could just be a corroded junction or terminal.  maybe some hambone tapped it for a custom stereo or something.  You have to go a few feet at a time untill you narrow down your problem area then dig deeper .  good luck  

make sure u have a good ground from the pump to frame to batt