Headlights, Radio, and Wipers work without ACC power

[TommyGuns]

Issue is in the title. The information in this forum has been invaluable. From the shared factory service manual, to the wiring schematic, to the posts sharing troubleshooting experience, I wouldn't be able to get to this point without everyone's contributions. But.. I've run into an odd issue and looking over the wiring schematic, I've found it doesn't make sense.

I have a new to me 83 K10 Silverado with a 350 SBC, and it has been fighting me ever since I got it home. My current issue is is that I had to replace all of the wires to the starter solenoid, except the 2 AWG positive battery cable. The only changes I made were to use silicone insulated wiring, route them lower (along the oil pan), and sheath the new wires in Techflex Insultherm heat protection sleeving. I did not use any butt connectors, instead sourcing the various Packard 56 and 59 terminals to crimp on to the new wires for the 2 pin alternator connector and the 8917253 firewall connector. The old wiring appeared to match the wiring diagram, and the new wiring I installed matches the diagram and the old wiring. Or so I thought. Obviously I messed up somewhere, as now the headlight, the radio, and the windshield wipers all work without the key in the ignition, but they did not do this before I rewired.

Trying to figure out where I messed up, I went over the wiring diagram again, and what I don't understand is that battery positive power seems to be wired in a loop.
From the Positive terminal on the battery, power goes to the starter solenoid + post, and from there power goes to both circuits 2A and 2H. 2A is a fusible link that then goes to 2B, which is a 10 AWG wire direct to the firewall junction block. Circuit 2H is a fusible link that is immediately spliced into circuits 2G and 2J. Circuit 2G goes to the positive pin on the alternator 2 pin connector. Circuit 2J goes to the top left Packard 56 pin when looking at the face of the large firewall connector. However, from the firewall connector, circuit 2E (a Packard 59 pin, middle row, 2nd from right) also goes to the vicinity of the junction block, where it is spliced with circuit 2C (which connects to the terminal post on the alternator) into circuit 2F, which is a 16 AWG fusible link that is then connected to the firewall junction block. According to the diagram, that junction block then has the 8911698 plate, call it a bus bar I suppose, which then joins the two circuits together.

Is this correct? Are there any suggestions on what I could check to explain how everything works without the key? I attached a cropped diagram with my notes, and a picture of the beautiful problem child.

 

[TommyGuns]

It seems the forum squashed the diagram. Here is a clearer copy where my notes are legible.

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[Turbo4whl]

I would check the radio. The headlights brake lights and 4-way are always hot. The radio would have 2 feeds and possibly 3. Feed from the dash lights, feed from the accessory and maybe the third for a memory. Memory is always on too. If these were joined together then you could back feed the wipers through the accessory on the ignition switch.

 

[TommyGuns]

Thanks for the response!

I spent a fair amount of this afternoon troubleshooting, disconnecting both battery terminals, disconnecting the wires from the junction block and unplugging the firewall connector, then testing continuity with a multimeter to verify I didn't somehow swap a connection around. That's when I realized that when wired according to the factory diagram... the starter positive post, the positive pin of the 2 pin alternator connector, the positive post of the alternator, both sides of the junction block, and two pins on the large firewall connector would all have continuity unless a fusible link blew. Strange. I figured there had to be something I was missing so I posted here.

After posting this though, I kept looking at the wiring diagram on the cab side of the firewall and saw that both of those 12+ pins on the firewall connector appear to be wired to the ignition switch. I've read the ignition switch has caused electrical gremlins in other squarebodies. I went back outside, reconnected everything again (without any changes) and now the radio and wipers only work with the key in the ignition. So I guess the ignition switch will need to be swapped at some point.

Fortunately I don't believe the wiring on this truck has been hacked much if at all. It still has the factory radio. The only major changes to this truck were to swap the factory 305 to a 350, delete the catalytic converter and vapor canister, they paired the new motor with Hooker long tube headers, and it has an Edelbrock AVS2 instead of a factory carb.