Skoda Yeti Poor Start Electrical Issue

That sounds frustrating! When you say "interrupted", do you mean it's completely cutting out, or is it more of a fluctuating voltage situation? Have you checked the basics like the battery terminals themselves for corrosion or looseness? Does this happen regardless of engine temperature? You mentioned the wiring harness, are there any visible signs of damage or wear? Have you tried checking the voltage at the starter motor while attempting to start the engine? This could help isolate if the issue is with the power supply reaching the starter.

Thanks for the quick response! When I said "interrupted", I meant the continuous plus is cutting out completely. It's not fluctuating, it just drops. I have checked the battery terminals, they are clean and tight. The issue seems to happen regardless of the engine temperature. As for the wiring harness, I've visually inspected it, and I don't see any obvious damage, but it's hard to check it all without taking things apart. About the starter motor voltage, how exactly should I test it? Where do I connect the multimeter?

Okay, if the continuous plus is cutting out completely, and it's not temperature-related, a defective battery is the most probable culprit. While a faulty ignition switch or a break in the wiring harness could theoretically cause this, they are less likely than a dying battery. For testing the voltage at the starter motor while attempting to start the engine, connect the positive lead of your multimeter to the small terminal on the starter solenoid and the negative lead to a good ground point on the engine block. Have someone try to start the car while you observe the voltage reading. You should see close to battery voltage (around 12V) when the key is in the start position. However, considering that you describe the issue as an interruption, and you've already checked the fuses, I would suggest taking the car to a workshop to get the battery properly tested under load. They will have the equipment to determine if the battery is the problem.

Alright, just wanted to share the resolution. The battery was indeed heavily discharged and defective internally. Replacement at a workshop cost 290€ including the new battery and labor. Starts like a charm now! Thanks again for pointing me in the right direction!