1990 C1500 engine dont start

hey guys,

i got a problem with my 1990 c1500 5.7

today i renewd the battery-clamps and when i connected them i got a short circuit between the plus pole and the body for maybe half a second.

after that i had no more power on any electric device except the starter, the little battery-signal in the cockpit and the interior light.
all other lights, displays and the a/c are dead.

when i try to start the engine, the starter turns the engine, but there is no ignition.

before the short circuit everything worked fine.

i already checked the fuse box and the fuse for the fuel pump on the firewall.

now my theory:
there are 2 cables connected to the plus pole of the battery. is it possible, that one goes straigt to the starter (which still works) and the other one goes to the rest of the electrical which got damaged by the short circuit? and is there an additional fuse on the battery-cable?


maybe one of you can help me with this problem or had experience with something similar.

thanks for your help and excuse my poor english