Help please, 2001 Mercury Sable LS: I have EATC self test showing 2 fault codes, 24 and 51. Code 24 indicates a problem with the blend door and code 51 indicates a problem with the solar radiation sensor being open. I under that the two related. What should the proper resistance reading be on the sensor across pin 1 and pin 5. When I set the multimeter to audible continuity and touch pin 1 and pin 5, no tone is heard. Please help.