I have an '03 Blazer ZR2 4WD. When turning the key to the crank position, the dash lights flicker but there is no crank. You can hear a relay clicking but it still won't start. For a short period of time, if you moved the steering wheel and gear shifter up and down/back and forth simultaneously while pumping the brake pedal, it would start. Now this formula is no longer working.

I have replaced the key ignition switch, the neutral safety switch on the trans, and checked relays (still not sure if those are bad). My next idea is to replace the wiring harness for the ignition.

Battery, ground wiring and starter wiring have all been checked and are good.

Any ideas??