Climate Control Air Flow

[Croweater]

G'Day All

 

Our 1978 260z 2+2 is refusing to direct air where it's told to - I know it's a vacuum assisted system and I've gone over all the hoses and connections under the bonnet and I can't find anything wrong.

 

Any ideas on where else I should be looking? Please don't say under the dash - you need to be a 10 fingered gorilla with triple jointed arms to do anything under there !!!

 

Cheers

[T.A.P]

Check under the dash? 

 

Seriouly you will need to check under the dash, check the hoses for cracks and fitments adm the diaphrams. Also the vaccum distributor tends to leak over time and if thats the case you will need to remove and regrease it. Remove the seats if you need to that should give you more space to work with.

 

How long did you have your Z for? Maybe the previou owner made a mess last time he worked on it.

[Lynton]

Yes I agree with T.A.P check under the dash, there are 2 air duct points from the heater on both LHS & RHS the very high ducts travel to the demister the lower ducts feed the centre dash ducts and side air vent binnacles I think I am right in saying that and they do slip off the plastic demister duct very easily over time. If you are working under the dash use some safety glasses as the ducts have insulation inside them that will have broken down over the years and the dust matter will drop into your eyes. Note remember what position the ducts are in if you remove them completely. Lynton

[Croweater]

Thanks for the replies

 

Just to clarify, it's not the ducts themselves that's the problem - it's the vacuum assist that changes the airflow that ain't working. I've fixed it in the past by finding a split in one of the small vacuum lines under the bonnet but all looks good this time.

 

T.A.P - what in the heck is the vacuum distributor and where do I find it?

[T.A.P]

Croweter, the vacuum distributor locates just above the the fan switch, it has a climate control mode slider to the front panel which allows you to select, Air/Vent...etc

 

There should be vacuum hose routes from the engine to the vacuum distributor (also known as Vacuum Selector) labels S (source), check that you have sufficient vacuum at the end of the hose. If you do then problem most probably lies in the distributor (assuming the diaphrams and hoses are in good nick). You will need to remove it and change the seals and/or apply some grease or swap it over with another one, it's pretty self explainatory once you disassemble it.

 

Heres a pic of the layout.

 

[Croweater]

Ahhhh OK, many thanks will give it a go.