2005 Peugeot 407 3.0 V6 petrol (211 hp), approaching 400,000 km.

Why did Peugeot put this wiring harness connector right on top of the engine, where it's constantly exposed to heat?

After nearly 400,000 km, the connector has started melting and deforming, around the same time other plastic components in the engine bay became brittle and started breaking from years of heat exposure.

Even scrapyards won't sell me a replacement because theirs are melted too. I suspect this connector may also be responsible for some intermittent electrical issues.

Turns out, extending just three wires is enough to relocate the entire harness next to the fuse box/BSM module. Instead of 60-70°C, it's now exposed to around 20-30°C, and accessing the engine cover and other components is much easier.

Currently testing the new layout. Replacing the damaged connector is next.

Has anyone else dealt with this? Why was it designed this way?

New thermostat and it reaches the same as was with old. on idle it only reaches working temperature, why is that?

PEUGEOT 307, 2.0HDI