Seat Tarraco rear window heating problem

That's quite a pickle! I had a similar issue with my Tarraco. The rear defroster stopped working, and the windshield heating wasn't its usual self either. Did you notice if your auto defrost was also acting up? Have you checked the battery voltage?

Auto defrost, hmm, I hadn't really paid attention to that specifically. Battery voltage, no, I haven't checked that myself. Where would I even start looking for that? And how did you figure out it was the battery in your case?

Yes, the auto defrost was definitely sluggish. I eventually got the error memory read, and it pointed towards low voltage issues. Given the symptoms you described, especially the windshield heating struggling, and the stored error, a weak battery is highly suspect. To properly diagnose, you really need to have the battery professionally tested. It's best to visit a workshop; they can confirm if the battery is indeed the root cause and advise on replacement.

You were spot on! The battery was the issue. I had it changed this morning for 290€, and now the rear defroster and windshield heating are working perfectly again. Thanks a million for your help!