Air Flow Problems

[COMMY VP 666]

hey i just got back from regency and they didnt let me thru because i had no air flow going to the front demisters.

is this a common problem, any ideas,

let me know thanks guys

[Cheap6]

Is there air from any of the vents?

If it's floor only, vacuum leak somewhere in the vent control lines = search as it's a common problem.

If the fan isn't working at all, fuse, switch, possibly fan speed resistor (speeds 1-3) or fan motor. Relay if it doesn't work on speed '4'.

[rob drag racer]

defiantly a vac leak check the vac ball

[COMMY VP 666]

yeah fan work, all the vents work but the front demister

sorry whats the vac ball?

[rob drag racer]

if its switching the position of the air flow from face feet ect its not the vac ball

the vac ball is located under the passenger side gard a big black well ball looking thing its common for them to get cracked ect because of where they are located but as i said above its unlikely if its switching

if it dose turn out to be the vac ball its easy to fix with out a replacement just whack a small bolt in the end of the vac line that gos to it

[COMMY VP 666]

could it just be a loose, small hose thingy, just where the heater control part is, there are 2 main ones there, one of them is off, could that be the problem?, or even if i put it on still wont fix it?

[rob drag racer]

that will be ya vac leak cant hurt to put it on either way

[COMMY VP 666]

yer didnt fix my problem, any ideas dash is practically out to find the problem?

[Cheap6]

For whichever hose is not connected, the vent actuator that it goes to will not operate, so reconnect that first.

One possibility is that the vent control dial is leaking - you will be able to hear that hissing but run the engine to ensure that you have a vacuum source first. Behind the vent control dial is a rubbery "maze" that directs the vacuum to the hoses. The plastic bushing the dial rotates on wears and breaks the vacuum or the "maze" doesn't seal properly. If you are keen you could disassemble the dial and apply some rubber grease to temporarily reform the seal or just replace the dial assembly

With the vent control out you will have seen the vacuum hoses on the back of the vent control dial. The black hose is the vacuum supply (goes to the inlet manifold on the engine via a one way valve and the vacuum ball under the left hand side guard via a 'T' piece behind the inlet manifold). The other coloured hoses go to the actuators for each of the vent control flaps.

Find the hose that corresponds to the demister position on the vent control dial and trace that colour hose back to the corresponding vent control actuator - about the size of a squash ball and on one or other side of the heater/A/C box behind the facia.

When you find the actuator, and assuming that the hose is found to be connected at that end, check the operation and connection of the lever and vent flap that it is connected to by moving it manually - sometimes they stick. If the flap is sticking you might be lucky and be able to free it but otherwise the dash and heater box has to come out.

Also check that the actuator will hold a vacuum - connect a short piece of hose, suck, and check if it will hold a vacuum sealed against your tongue.