This post stems from the discussion that was happening post the Bright Run this year. http://www.ptcruisers.com.au/forum/view...43&start=45

I have been having a problem with the fan speed on my PT now for about 18 Months.

When taking long drives (Canberra - Melbourne) the fan speed would sound like it is operating flat out but no air would be coming out of the vents, even when turned to blow directly at the face, after about 3 hours on the road.

I have had the fan resistor changed with little effect on the problem.

This has got the dealer bluffed as well, this is in part due to the length of time that it takes to occur.

One of the things that he thinks that it might be is that at least one of the flaps operates off of vacuum pressure and may have a slow leak in the system that inturn will take a long time for the symptom to occur.

I will continue to monitor this to see if I can get any more information/data for the dealer and hopefully it will happen again as I get closer to the dealership when it is open.

Any Ideas?

Either a stuck flap but if that is the case it would still be coming out somewhere, like the foot vents or demister on the dash. Someone with a manual may be able to confirm this by I don't think this is vacuum controlled but mechanical. With the car off sit and turn the knob that controls the air direction. You should be able to hear something moving somewhere.

If air is not coming out anywhere but you can here the fan working I would look at the fan itself. It could be the fan impeller has come away from the motor. Listen to the fan with the car off. If the motor and impeller have separated you will hear the motor but it will be a higher pitch them normal and nothing else.

The only other thing I can think is a blocked air inlet in the cowling. Check if you have a pollen filter fitted, if you do this could be blocked but even then you should get some flow.

Good suggestions RT, but this is not a constant problem but one that comes over time and after about an hour or so stopped it goes back to normal for the next couple of hours.

This why it is getting to be a pain. If it was constant it would be alot easier to fix.

That is why I have lived with it for the past 18 months. This happens when the car in cool, AC or heating mode.

triggering a distant memory of THE fan blowing like the BEE jeezus and not "working" .... I turned it off .. opened windows & sun roof for air & turned on again it was fine .. only noticed it cause it was a stinker of a day ... I got in from having her parked in the sun ... thought nothing of it as such till now & that was last summer !! ... I don't use Plums & roses as MUCh as U do .. I will pay attention if it happens again ... wouldn't have anything to do with back preasure or temp difference on those flap things making them stick closed ??? ...

Same problem came down to blockages in AC ended at a AC specialist Chrysler was no good three time lucky before GORC but did play up coming back into Sydney. Going to Canberra tonight we will see what happens.

I think RT might be on the money with the VACCUUM issue....(good call Rob)
Could be one of those inline pods on the hoses or a hose that's collapsing because it's become soft... it wouldn't neccessarily do it all the time.

Gonna be difficult to isolate the problem--- - I'll have a look at the diagnosis chart on the workshop CD - but don't hold your breath...it's fairly uninformative.

Good luck and cheers Scottie