Cooling unit is wonky

Ford Ford Advice Ford Fairmont Ford Fairmont Advice Ford Fairmont 1992
...
My 1992 Falcon Fairmont Ghia has a problem with the airconditioning. When the outside temperature is 30C-35C and the inside is set for 24C, the unit suddenly changes over to heating and the fan speed goes to nine. This has happened when driving normally on flat roads, when parked at idle and also once on start-up. Our local auto electrician/aircon service man was present once when it happened and dialled in the ``show fault'' codes. But the computer showed no faults.

I ASKED Mark Lynch of Carcool for his opinion. He thought the fault could be either the ambient temperature sensor or a faulty climate-control unit itself. The ambient sensor behind the front bumper tells the climate control the outside temperature. If this goes open circuit, the control will assume that it is -50C and will switch to full heating. The climate control unit itself could have a faulty component, dry-joint in the board, or bad connection plug. Try changing the ambient sensor and clean its connector. If it fails again, replace the climate control head.

Disclaimer: You acknowledge and agree that all answers are provided as a general guide only and should not be relied upon as bespoke advice. Carsguide is not liable for the accuracy of any information provided in the answers.

Comments

Have a new question for the CarsGuide team?
More than 9,000 questions asked and answered.
Complete guide to Ford Fairmont 1992
Complete guide to Ford Fairmont 1992 CarsGuide Logo
Reviews, price, specs and more