Peugeot 208 starting issue

I had a similar issue with my old Renault Megane. Terminal 30 is the main power supply from the battery. In my case, the problem turned out to be a bad ground connection causing a voltage drop. Have you checked the grounding points, especially near the fuse box and starter motor? It could be a simple fix.

Thanks, that's helpful. Where exactly should I be looking for these grounding points? And how would I check for a voltage drop? I have a multimeter.

On the Megane, the main grounding point was bolted to the chassis near the battery and another near the starter motor. A loose or corroded connection there can cause havoc. To check for a voltage drop, set your multimeter to DC volts, connect the negative lead to the chassis ground, and the positive lead to the positive terminal. Then, try starting the car. If the voltage drops significantly (more than a volt or two), you likely have a bad connection or a wiring harness issue. However, considering it might be the battery itself, I would advise visiting a workshop.

Appreciate the advice. Took it to a garage, and you were right - it was the battery. New one fitted and all good now. Cost me 290€.