Ignition Switch Power Supply Cuts Suburban Dead

Had the same issue with my 2019 Chevy Tahoe diesel last winter. The problem turned out to be more than just the ignition switch, it was a combination of corroded battery terminals and a voltage drop across the main power circuit. Initially thought it was just the ignition switch due to similar symptoms, but after proper diagnosis, found multiple issues: Significant corrosion at battery terminal connections, Faulty circuit break in the ignition system, Compromised power supply to Terminal 15 The fix required: Complete terminal cleaning and replacement, Rewiring of main ignition circuit, New ignition switch assembly It was a serious electrical system issue that could've led to bigger problems if left unaddressed. The whole repair took about 6 hours at the shop. Would strongly recommend getting a proper diagnostic test first, the error code alone doesn't tell the full story with these systems. The most important thing is checking all power connections before replacing the ignition switch. Often, what seems like a switch problem is actually a power delivery issue from corroded connections or damaged wiring.

Thanks for sharing those details about your Tahoe repair! Had almost identical issues with my Suburban last month. The mechanic traced it through the wiring harness and found multiple problems, including a bad starter solenoid and some damaged relay switches. The fuse box also needed attention due to some corrosion. Can you remind me what the total repair cost ended up being for your fix? Just want to compare since I'm still dealing with occasional electrical gremlins, sometimes my power windows act up now. Wondering if that could be related to the original ignition switch problem or if it's something new I should look into.

Good to hear back about your Suburban! After seeing the mechanic, my Terminal 15 ignition positive issue got sorted, turned out it was just a loose cable connection that needed fixing. Total bill came to 95 for the repair, which wasn't too bad considering all the initial worry about it being something major. Those power window problems you're having sound like they could be connected to your wiring harness issues. When the main electrical system gets compromised, it can cause all sorts of weird secondary problems. My car won't start situations often trace back to seemingly unrelated electrical gremlins. I'd recommend getting those windows checked out while the earlier repair is still fresh in everyone's mind. Sometimes these electrical issues can cascade if there's still a loose connection or damaged relay switch somewhere in the system. Might be worth having them take another look at the fuse box connections too, since you mentioned there was corrosion there. The good news is that once you get all the electrical connections properly sorted, these problems usually stay fixed. Just make sure whoever looks at it checks the entire circuit, not just the symptoms.

Thanks everyone for the input. Took it to a new mechanic yesterday and finally got everything sorted! The car won't start issue ended up being exactly what you all suggested, a combination of problems in the electrical system. The mechanic found a corroded battery terminal that was causing voltage drops, plus a damaged wiring harness near the starter. The circuit break in the main power line was also shot. Total repair came to about €450 including parts and labor. Best part is they did a complete electrical system check and found the cause of those power window issues too, turned out to be a loose ground connection. Everything's working perfectly now, and they even showed me exactly what was wrong so I know what to watch for in the future. Really appreciate all the advice about getting a proper diagnosis first. Saved me from just blindly replacing the ignition switch, which wouldn't have fixed the real problems. The new shop did great work and I finally feel like I got my money's worth on a repair.