NO, I want everything to be stock without additional equipment

Hello guys, I also have a problem with the driver's seat, it doesn't heat up at all, I checked the voltage at the plug and it shows 14.5v but with pulsations from 4.5v to 14.5v with all 5 dashes on the board, if I drop the dashes the maximum voltage also drops, for example at 2-3 dashes the voltage ...