I do not know the Peugeot much, but in the diesel the switchboard can work alone without having connected the bulb to the thermostat, I have a fiat siena and tube that problem, disconnect the blue bulb of the thermostat and the switchboard works alone but the only thing that the switchboard is a timer and delay more time in your tablage of controls in off the light of the preheating.眼睛要非常小心地通过可能直接伤害它们的电流的错误。