AC not work until 08 MKX moves

[JohnJeffries]

My wife's 08 MKX does not engage AC compressor when first started (after sitting). It will not kick compressor on and cool no matter how long you sit after first start. Once in gear and moving it will freeze you out. Even if you stop and park for a while (after driving), it blows just as cold. The failure is only between first starting engine and driving down road. It does have the controls where you set the temperature. Local shops say "we have no idea" and "bring it it" which I translate to let us give you a huge bill for diag. Any thoughts on where to look will be so welcomed.

John J

 

[11MarkX]

Only thing I could think of is a stuck A/C door. You'll have to research if you can get to the mechanism and try to lube it. Could also be a very dirty cowl or cabin filter which will also put more stress on your A/C heating system? I know it sounds silly, but if little air is allowed to move in the A/C system, (when parked), the A/C door may not open until you start moving and introduce more air flow from the cowl? That's weird. If you find out why, please post.

 

[JohnJeffries]

Only thing I could think of is a stuck A/C door. You'll have to research if you can get to the mechanism and try to lube it. Could also be a very dirty cowl or cabin filter which will also put more stress on your A/C heating system? I know it sounds silly, but if little air is allowed to move in the A/C system, (when parked), the A/C door may not open until you start moving and introduce more air flow from the cowl? That's weird. If you find out why, please post.

The filter is new and I do not believe it to be the door. When it runs, I can hear the AC compressor. The compressor is about 18 months old and I have been able to hear it (not loud) since it was new. During the "no cold air when started" behavior there is no sound from the compressor. after vehicle starts moving I will hear the compressor start up and the cold air starts at once. Once it starts working it will freeze you out even in the hottest weather.

 

[Haz]

Are confident your MKX's electric cooling fans are operating properly?

A lack of cold AC with vehicle at rest, followed by cold AC once underway, more often indicates an inoperative cooling fan, causing air flow through the AC condenser to be insufficient for cold AC until the vehicle is moving.

From a cold start, the driver side cooling fan should immediately begin running when the AC is turned on, followed by the addition of the passenger side fan running as the engine creates fuller cooling fan demand, or if the AC is set to Max.

Good luck!

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[JohnJeffries]

UPDATE: radiator fans died completely today. All local stores do not have this part (can order, but their brands have terrible reviews), online sales like Rock Auto and others are a week to get here (if then). The only right now options was the dealer one town away. Wife does not want her car stuck for a week so off I go. After a little internal sobbing, I paid for the part and headed home. 20 minuets time (I did some cleaning while apart) and fans work, engine is cool and AC will freeze your eyebrows off. Thank you to Haz for the suggestion. When I checked the fans, the could not start when car started, but a physical "bump" or the wind of driving would start them. I was shopping for a good price when they bought the farm.

 

[Haz]

The price difference for the Motorcraft cooling fan assembly is a worthwhile investment, and, the value of a satisfied spouse is priceless.

Good luck!