I have RX 300 Lexus. The air conditioner works. When I tried the heat for the first time it only blows cold. No heatt. The fuses look fine. I just bought the car and never checked the heat. Any thoughts.

Check your coolant level. Water pumps are common on these to leak, and the incorrect coolant level will affect the heat.

I presume the repair has been made. I helped a co-worker with her 99, same symptoms. This has an elaborate climate system, accessed behind the glove box. Allow several hours, and at least $160 for the new air mix servo, the likely culprit. There are 2 others, the mode servo (floor/vent/defrost/mix), and recirc servo, less likely, since heat is the issue here. here is a forum link, a little googling will show the process. http://us.lexusownersclub.com/forums/topic/71031-no-cabin-heat-2000-rx300/ The Lexus dealer charges $500 and up to fix this.

My 2007 RX350 no heat from the heater. It turned out the water level in the radiator was VERY low. Once I topped it off I got my heat.

I have an rx300'heater works but air conditioner will not cool