2000 Pontiac Grand Prix GTP crank no start
One morning got in my car turned the key and
it turned over then I lost all power everywhere.
The battery ground cable had a poor
connection so I cleaned it and tightened it.
Now it turns over but I have no fuel in the rail
(jumping the relay provides pressure but goes
away when turned over) and I’m assuming no
spark because when I leave the fuel pump
relay jumped, pump running, it turns over but
does not fire. No communication with PCM.
Tried replacing pcm. No communication no
security light. Replaced crank sensor and fuel
pump resistor, relay and fuse. Have been
diagnosing for weeks with no joy. Thinking
bad PCM harness? Also some fuses (A/C
clutch and TCC) have 5 volts and are blown.
Pcm to fuel pump relay has continuity but only
5 volts. Battery brand new. All fuses are intact
now and all relays have been swap tested and
bench tested to be good. Looked everywhere
for answers. All help is appreciated.