manest

If your AC/Heater Blower speed always runs 1) low or 2) high, see attachment for fix.

The most likely cause is the linear controller module for 1) , and the resister (resistor) for 2).

It is rarely the $850 electronics module in the dashboard.

This is poorly documented in the available publications and even Lexus service was confused and provided incorrect info.

I will be happy to provide info in pdf, but was not able to attach. If you tell me how, I will.

I have this same problem, blower only runs on high. It started after someone stole my stereo and so kindly cut all the wires to the AC control head. So I had to get the plug ends from a salvage yard and re-wire the whole mess, not to mention a new control head. Now the blower only works on high speed. Yes, it is wired correctly. However I did get it wrong the first time because there are several wires that are color coded the same. So I may have caused something to "burn" out. Anyway if you could send the file to me I will greatly appreciate it. marioanest@gmail.com

I hate to be the bearer of bad news, but it is most likely a blown head gasket :( I'll go as far as to say it is probably the #6 cylinder. Don't ask me how I know!!