Heater Controls - Air stuck on screen.

[tractionman]

I have just been out in the griff and set the heater to demist the screen. After a few minutes I re-directed the air back down to the dash vents but nothing happened. I stopped and tried the air direction control to see if it still made a whirring noise when turned. The motor runs and changes direction with the knob but never stops. My guess is some sort of linkage has come adrift. Any ideas what to look for and where?

>>> Edited by tractionman on Wednesday 18th December 18:47

[tractionman]

Panic over - Just been upside down in footwell and found that the grub screw holding the control arm on the end of the servo was loose.

[vodkakid]

how easy is that grug screw to find?
i might have the same prob

[KeithS]

I have the same problem - air only blowing on the screen - but when I rotate the knob there is no motor sound, so I assume that the servo is knackered. I have the same problem with the recirculate/fresh air one too. Anyone know if it is usually the servos that go, and if so, how easy are they to replace?

[tractionman]

It's not too bad to find. I will try to take a photo and post later today.

[beano1197]

Must be catching!

This morning, I had the blower on full and carefully turned the dial to vents from screen and the motor worked nicely. Three seconds later the motor whirred away of it's own accord and directed the air back to the screen - wouldn't budge after that!!! TVRs - dontcha just love their little quirks?

There is a little unit which has all the electrickery bits - I think starting point is to check all the connections which probably rattle loose over time.

[vodkakid]

its seem that no matter were i want the air it comes out of the screen and footwell anyway

[Prince_Charming]

vodkakid said: its seem that no matter were i want the air it comes out of the screen and footwell anyway

Yup, I've found this as well - it's usually cold as well. Might have to get some string-backed gloves....

[griff430]

I've found that the servo sticks sometimes on my Griff. I usually just pull back the carpet in the footwell, and give it a helping hand. You can see if the servo mechanism is working, by adjusting the heater controls when the carpet is pulled back.

[tractionman]

Vodkakid, here is the photo of the heating servo units found under the dash by the glove box. One is air direction (screen or dash vents) and the other is the temperature control valve. While I was fixing the air direction grub screw (marked on the photo), I noticed that there was a small potentiometer on the end of each servo unit presumably giving some sort of feedback to the heating control unit. Having had problems where I can only get hot or even hotter air I decided to investigate further. The potentiometer is adjustable (by turning) within a small range and allowed me to set the stop point better. I set the temperature control knob to cold and then adjusted the potentiometer to give max travel in the cold direction and amazingly I can now get cold air out of the vents. I hope that all made sense.
Neil.

[davidd]

I had Marcs (Mr CHarming to you) old Griff and found the switch to be utterly useless, I used to find the easies way to control the air was to close the black vents in the footwell, that what the air has to go onto the screen.

Marc, if it is not blowing hot ait then you have the settings in the wrong place, you need to turn the top left hand knob all the way to the right, ie away from the red dot.

You think Griffs are bad...you should have seen how long it took me to defrost the cerbera this morning.

D.

[Ballistic Banana]

Dont Forget there is the Drivers own 3 step fan controller under the Steering wheel that just blows cold air in the drivers footwell and right hand center vent i Think.

BB

[Toffer]

I think the footwell fan system disappeared on later Griffs...