Trailblazer Intermittent Ignition Issue

Whoa, sounds like a gremlin in the system! Intermittent issues are the WORST. The flickering dashboard lights are a huge clue though. Have you tried jiggling the ignition key while attempting to start? Sometimes a worn key or a faulty key cylinder can cause similar problems. Also, when it shuts off, does it die instantly, or does it sputter first? Knowing that could help narrow it down. I'd definitely double-check all the fuses related to the ignition and fuel system, even if they look okay visually. Sometimes a hairline crack can be hard to spot. A multimeter is your friend!

Thanks for the detailed reply. The engine usually dies instantly, no sputtering. I did try jiggling the key, no effect. When checking the fuses with a multimeter, what resistance value would indicate a defective fuse?

Okay, instant shut-off points more towards an electrical issue rather than fuel starvation. As for the multimeter reading, a good fuse should show nearly zero resistance (continuity). Anything significantly above that, even a few ohms, means the fuse is compromised and not conducting properly under load. Given the symptoms, and the fact that jiggling the key had no effect, I would start by carefully checking the ignition switch itself and all its wiring. But honestly, for something this critical, and if you're not completely comfortable digging into the electrical system, I'd strongly suggest taking it to a trusted workshop. Intermittent electrical problems can be a real pain to diagnose, and you don't want to risk getting stranded.

Appreciate the advice. Indeed, I took it to a workshop. It turned out to be a defective fuse, as suspected. Total repair cost was 52€. Thanks again for your help.