Résistance élevée dans le câblage du contacteur

Resistance in a switch's circuit high enough to change what the module reads, though the circuit is continuous. Many switch circuits are not simple open-or-closed — they use pull-up resistors and defined voltage bands so the module can tell a pressed switch from a broken wire — and added resistance moves the reading into the wrong band.

So the module reports an implausible state rather than a dead circuit. The circuit tests as continuous, which is what makes it hard: a meter's test current passes a corroded joint that a signal circuit cannot. Measure the voltage the module actually sees in each switch position rather than continuity, and compare against the specified bands — that is the only test that finds it. Corroded connectors and poor previous repairs are the usual causes.