Ford Repair: flashing heater dash lights, dash lights, 2004 f 150

Question
I have a 2004 f-150, last night I noticed that the lights on the dash for the heat and a/c started blinking off and on every 3 seconds. This morning I noticed it again. What could it be?

Answer
most likely you are experiencing a wiring proble to the body module. very common concern in this year. if you were to remove the driver's and pass side siil plates, ( the cover that is on the floor near the door opening, it just pulls up- either side you will find wires saturated in water or evidence water was there and find a wire or two that has corroded