heater goes to cold after a short drive adjusting the temperature does not help after car is parked a while it will work again then goes cold a short while
First check the coolant level when the engine is cold. If that is ok you may have an open thermostat but this will require hands on testing by a technician. Here is a link to find a shop near you.
https://repairpal.com/repair-shops
Alex
RepairPal Certified shops can diagnose and repair your 2004 Lexus LS430. They provide transparent pricing with a minimum 12-month or 12,000-mile warranty on repairs and services.