I have a 560 SEC -88 , here in sweden its about -10 celcius and when the engine temp rise the fan start and it start to blow warm air but after about 10 min the fan just blow cold air if i then stop the car turn the ignition off and start the car again the air is hot and nice again .....for about 5 min and then just cold.... this problem has started now... any ideas???

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-88 560SEC
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