Sierra6

and other times, you turn the key and nothing. no lights. no starter. The ignition switch and key lock were replaced in 2014. They also said "repaired wire harness at starter"

The starter wires still look rough. you can see wire in some places.

However, i took the ignition switch out last night. we have 4 volts at the red wire in the blue connector, and 4 volts at the red wire in the black connector. ( I was told these should instead have 12 volts)

we checked the voltage at the bulkhead connector. We get twelve volts at the top left red wire. four volts at the top right wire (that someone is telling me shouldn't exist), and Four volts at a red wire below the top left wire that reads 12 volts.

We checked and found continuity between each of the red wires at the ignition switch, and each of the three red wires at the bulkhead connector.

It's worth mentioning that this car has always had this problem, and in the past, has had an aftermarket alarm system put in (I thought we had successfully and safely removed it). I haven't checked the safety neutral switch. But would it stop all the lights from turning on on the dash? I haven't checked the ignition pin at the C100 yet either. (Someone said it's on the engine side of the firewall, is this true?)

It seemed to be working ok until i replaced the alternator a few days ago. the car hasn't actually cranked since i replaced the alternator. i've been working on a high idle issue and haven't got my timing right yet.

I have done the three wire 02 sensor mod, and i wired it to the MAF for power per a writeup on here. (i was afterwards told that was a bad idea, could cause draw issues, and I'm getting a code 34)

Thanks for any help. Most threads i've searched talk about VATS, and i can't find one that addresses my low voltage questions.

Car is 1985 Firebird Automatic with 3.4 swap

Vader

Instead of location, can you identify which pin designations in the C100 connector have power? For example, pin G5 should have battery power, pin A4 should have power from the ignition switch.

Sierra6

thanks for the reply Sir. I actually gave up and took it to the shop. they said they found and replaced three burned fusible links. ignition is fixed. no-start mystery still remains. they're doing further diagnostics. everything on the engine is new (including the engine) except the MAF.