Excursion Rear AC Not Cooling

Sounds familiar. I had a similar issue with my old Opel Astra. The air distribution went haywire, and the AC stopped cooling in the back. Have you checked the cable connections to the rear ventilation unit? A defective plug connection can cause this.

Where exactly are those cable connections located? Is it something I can check myself, or is it buried deep?

On my Astra, it was behind the trim panel in the rear passenger footwell. But honestly, tracing electrical faults can be tricky if you don't have experience. Given it's an automatic climate system, and you're seeing errors, you might be better off getting a workshop to take a look. They have the tools to properly diagnose it.

Thanks, I appreciate the advice. I'll take it to a workshop. They found a defective plug connection. Repair cost was 95€. Everything works now.