Unless your servo is leaking, it may not be the issue. Remember the chain of events on the servo system....aux water pump freezes, thus blowing the amplifier, the servo doesn't usually get affected by these events, as long as the little motor inside turns...it is likely fine.....Also remember there is a sensor tube behind the glove box, this turns to dust, with out it, the system won't be able to tell the cabin temperature.

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