|
When changing the air flow settings while the engine is running there should be some audible servo and vent movement from the air distribution box and/or hissing. So something's not right with the vacuum control system and that could easily be your entire problem. Perhaps a hose got pulled off or split, the check valve (near the engine) has failed or a couple of servos have gone south. Blip the engine revs and as it returns to idle the vacuum boost might make something move if the leak isn't too bad.
One less likely thought I had was the air intake under the cowling (at the base of the windshield). If the air intake there is somehow blocked then that would restrict air flow. It might also be what hastened the demise of the original blower. It's not uncommon for the screen under the grate in the cowling to let go of the mastic and drop down, allowing leaves, needles, other debris as well as vermin to get in. The air intake is actually fairly well protected from debris so I'm a bit hesitant to say this is a likely cause. Any debris that does get into the cowling normally blocks the drains first, resulting in interior water leak problems in the passenger foot well. It's still something to keep in mind though, especially the vermin thought.
--
Dave -940's, prev 740/240/140/120 How time flies when you're having fun
|
