im getting my uncles 96 s10 4.6 2 wheel drive. Well it has a problem that is blowing my mind. heres what i know.

fuel pump does not activate but works hooked up to a power source. it starts when i have the fuel pump hooked up to another battery i turn the key it fires up reves high then dies. relay works both, fuse is good. i do have the bed off dont know if i affect any neutal or negative. need more info let me know.

 

have you checked the fuel pump relay?

 

Well it should work when switched with my horn i swapped right?

 

are you talking about the horn fuse?
Facing the the front of the vehicle, there are two relays mounted next to each other on the firewall driver's side. the right one is the fuel pump relay, the left one is the ac compressor relay. have you checked this relay?