My 406 coupe brake lights are staying on when ignition is turned off, garage did a quick reci and took out the switches under dash drivers side but to no avail. Only way they go off is if I disconnect the battery.
Hi Steph, not sure which 406 you have but most commonly on the 406 the drivers foot well gets wet. Whether that be leaking door seals or a blocked and leaking sunroof drain.
In the drivers foot well there are multi pin electrics. When they get wet the most common problems are electrical problems such as brake lights being erratic or staying on.
Check the foot well for dampness, pull up the carpet if necessary to inspect said multi pin connector. If all looks okay and well I'm not sure what else to suggest.