Lexus Repair: 1994 Lexus heating problem, lexus service, toyota repair

Question
We have a 94 Lexus that has been an excellent car with one difficulty.  The
heater won't blow hot air.  Diagnostically the heat/ac is in fine.  We have
checked most everything, yet can't get hot air to blow.  We have even stumped
our local Lexus Service Manager.  I am trying to locate a diagram or schematic
to see the cable that operates the door that opens to allow heat in, but have
not found it.  The cable seems to be in working order, but since I've read
through some of your answers, I'm wondering if it may be the motor that operates
that door.  Can you help me trouble shoot this, or if you have a different idea
of what my problem could be, could you please share it?
Thanks so much!


Answer
Hello Sue,
  I would inspect the coolant inlet and outlet hose. When The heater control working properly, the outlet temp hose should be the same as the inlet. Have someone adjust the temperature and you will see the cable move up and down.   Make sure there isn't any air pocket in the cooling system.  Use a 17mm wrench and open up the coolant refill neck. Open up the reservoir bottle. Fill up the coolant through the refill neck. Race the RPM up to 2500rpm and hold it for 3 minutes.  Turn on heater MAX.  By doing so, You are getting the air pocket out of your cooling system.  Inspect your air blend servo.  Remove the glove box compartment.   Check to see if the doors are working.  Please let us know if we can help you further. Thank you for you question.
JP IMPORTZ
DALLAS/PLANO INDEPENDENT LEXUS AND TOYOTA
REPAIR, SERVICE AND PERFORMANCE
WWW.JPIMPORTZ.ORG
214-221-3135