1996 Mercedes Benz 280 airflow

1996 MERCEDES BENZ 280
187,000 MILES
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WALTER PICHT
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  • 1 POST
The air flow in my car will only come out the top defroster vent and not switch to the foward vents or the floor vents . The a/c and heat both still work .So I can change the temperature but the air flow stays in the same place
Jun 22, 2013 at 7:26 AM
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CARADIODOC
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  • 34,306 POSTS
Sounds like the system uses vacuum motors to change the mode doors and that vacuum hose is broken or disconnected. Most of those systems are spring-loaded to default to the defrost position for safety. Your feet might freeze but the windshield will be clear. Look under the hood for a small plastic vacuum hose going to the firewall. There will also be a small check valve in it. Those valves don't cause much trouble but it could be plugged.
Jun 22, 2013 at 10:18 AM