heater not working

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Nov 4, 2006 | 02:05 PM

adrenaline8158

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Joined: Nov 2006

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heater not working

i have a 99 superduty with a 7.3 but the heater is not working right the only thing that works is the defrost. no matter what position the switch is on it comes out the defrost. could it be a switch or maybe a vacuum problem. I looked at the vacuum lines but they all look ok any suggestions

Nov 4, 2006 | 05:06 PM

tjc transport

i ain't rite

Joined: Mar 2005

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From: Marlboro Mental Hospital.

defrost is the default position when you loose vacuum signal.
i am not sure on the 99 if it is a switch problem, or something simple like a broked line though.

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