406 massage seat failure

I had a similar issue with the massage seat in my Peugeot 406. From what you're describing, it sounds like a break in the circuit, like a dodgy cable or connector. Have you checked the wiring and plug connection under the seat? These things can come loose over time, or a wire might have snapped.

Thanks! I'm not really sure how to check the cables properly. Is it easy to get to them? Do I need any special tools?

Accessing the wiring isn't too difficult, but it can be a bit fiddly. Disconnecting the battery is always a good idea before fiddling with any electrical connectors. If you're not confident with automotive electrics, it might be best to get a workshop to take a look. I spent hours on mine before finding a broken wire. Ended up being simpler to have a professional sort it. You could try locating a wiring diagram, but even then, tracing the wires can be like finding a needle in a haystack.

Thanks, I appreciate the advice. I think I'll take it to a workshop. They quoted me around 95€ to diagnose and repair the cable or plug. Sounds like a fair price to save myself the headache.