Hummer 3 Ignition Question

[f5fstop]

Originally posted by dei???????:
Test lights are evil.

Did you try disconnecting battery for like 15 min? The test light could've given it a little voltage and, blew a fuse, triggered anti-theft, or initiated some system wrong and got it stuck.

Anyhow, for when you get it back. I recommened going directly to the battery for your power source. That's what I did, as the ignition harness is thin gauge and I didn't want to mess with it.

I agree, with dei, test lights on electronic circuits are not only evil, but a bad idea. Electronic circuits draw milliamps, test light can draw amps. Too much current through an electronic circuit can fry something (also known as letting the smoke out of the box).
Always use a high impedance multimeter.
Here is a copy of a short, but to the point GM bulletin:
Test Lamp to Ignition Control Module Circuit Connector Notice
Notice: Do not leave the test lamp connected to the PCM IC circuit connector for longer than 5 seconds at a time. Failure to do so may damage the ignition coil and/or the Ignition Control Module.

Did you check all fuses in the circuit?
Batt IGN Fuse 5
IGN1 Fuse 33
STRTR Fuse 85

Then if those fuses are ok, check the following relays, you should be able to pull a relay from the A/C circuit or another circuit not required to run the vehicle and do a swap with one of the following relays:
RUNCRNK Relay 78
PCM CNTRL Relay 77

If all fuses and relays are ok, not sure what to tell you. It could be any number of items including, but not limited to a fried BCM or PCM; depending on which wires you were testing.