thumpr

having a problenm with the air vents on an xe - when the engine is off and the fan is on, it will only blow air to the screen, but when the engine is running it only blows to your feet. the screen, high/low etc settings make no difference.

all the vacuum hoses seem to be plugged in ok, though i havent checked behind the actual sliding selector - any ideas??

thanks

Futura97

If its like an XF, then take out the glovebox and have a look at all the vacuum pipes behind. Check to see if there all plugged in properly. If this is ok maybe you have a dodgy switch or a pipe is blocked somewhere.

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EL driver...

LTDHO

It will only blow to the winscreen when the motor is off. Ya need vacuum to opperate the air locator. Remove the glove box and with the engine running change the position of the swich and watch the leavers.

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thumpr

LTDHO - exactly what switch do i change ?

the only switch i see behind the g.box is the hot/cold switch

tonyk

My XD does the same thing roughly. All the pipes inside the car are attached where they should be.
In my case it is the selector assembly.
It is directly behine the dash mounted slides where the direction and temp slides are.
There is a round rubber diaphragm which seals the directional slide. They get old and perish and allow air to leak away rather than holding a vacuum to any particular set of vents.

If you run the car for a minute and build some vac then slide the switch over and turn car off. Moving the slide from one end to the other will result in a hissing from behind the slides if the diaphragm is leaking.

Its a p.i.t.a. to fix (hence I have nothing but demisters)

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Well done SA pollies (for once). Hoon laws are long overdue to protect car enthusiasts against idiot drivers.

LTDHO

sorry thumpr, I ment toggle the selector assy, and with the g/b removed you should see the actuators move.

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Cobra188

thumper - first thing to check is the non-return valve on the engine side of the firewall - take it out of the line (first identify the way it is pointing as it has to be fitted back the same way) to see if this makes any difference - if it acts the same with the valve removed try a known good valve in place and try it. If it works problem solved. If not then you have to start tracing vacuum lines into and out of the direction selector switch middle of dashboard. This is not too hard to remove - visually check all lines - it may be obvious straight off which one/s are broken or just fallen off the connector - if they have opened up on the ends and fallen off simply cut 5 or 6 mm off and rejoin - if nothing is obvious start the engine and listen for leaks as you operate the slide control through all positions. If you still can't identify the cause try a known good slide control and hope that fixes it. If not, you then look to the servo ends of all the vacuum lines which are behind the glove box and under your centre dash area on the heater box. One or several may have come off in a similar manner to that I described above for the main connector - same diagnosis procedure applies - good luck!

thumpr

Cobra188 > i dont think i even have the non-return valve. from the manifold the vacuum hose runs towards the firewall then splits into two seperate hoses before going thru the f.wall - but no valve.

should it have one? i guess it should. its on a 351.

i'll check it out on my other xe tonite.

XDSedan

So if your selector switch makes a hissing noise when you change positions, it's stuffed? I thought this was normal since it still selects the correct vent. Please explain, can it be working but not 100%? I would of thought if there was a vacum leak then it wouldn't select the correct vent or slowly move back to the windscreen? Thanks

gregaust

XDSEDAN,you will get a bit of hissing as you move the selector,but the hissing should stop when you have selected the position you want..