Smiths F390 Fresh air heater on a 65 TE21

Has anyone got a diagram and / or description of operation for this heater box. It has more levers and cams than enough and I think mine, though re-built is incorrectly adjusted since the bottom flap that lets air into the car never fully closes and I cant seem to get any air flow to the screen. I don't want to pull the thing out to look at whatever internal flaps there are if it's simply a matter of adjusting the levers and cams on the outside of the box. From a diagram I know I can fathom out how it works, Thanks Steve Haycock Posted by haysx0 01/05/2016 13:50:53

[attachment=0:l9efh2b4]<!-- ia0 -->P1020042.JPG<!-- ia0 -->[/attachment:l9efh2b4]  Hello Steve, I had the same problem with my TF21 and I suspect it may affect many later 3 litres. The cam lever wears way until it is concave and has virtually no effect on the heater flap, if I remember rightly it's the one on the near side of the heater box. I built it back up with weld and then filed it back to the profile as shown on my picture, if you look carefully you can make out the new metal I have added, when you take yours off it will be obvious where the weld needs to be. The flap on my car now opens fully in operation.  Cheers,   Andrew Wisdom Posted by tf1695 01/05/2016 18:59:29

Thanks for the reply but my cams look ok and the problem is that the flap into the car never closes except when you turn the temperature knob to off, so I don't seem to get air to the screen. What I really need is a diagram showing the flaps inside the heater box and / or a description of what happens to the external and internal flaps through the various stages of moving the distributor knob. I re-built and upgraded the blower on my TE and get a good gale now but not it seems to the screen!   Steve Posted by haysx0 03/05/2016 16:11:37

Steve On my mostly unmolested TE with the LH &amp; RH knobs fully anti clockwise  reading is OFF at 12 o'clock  and the flap into the car is is fully closed. As soon as you move RH knob  slightly clockwise the flap fully opens &amp; hot water enters the heater.The further you turn the hotter it gets until the reading is HOT .If you then turn the   LH knob clockwise you alter the amount of air coming into the car, when you are fully clockwise the reading is MAX and the flap into the car is virtually closed so nearly all the air is going to the screen, maybe the flap should fully close and send everything to the screen. Presume you have checked the hoses from heater box to screen ,they can disconnect/puncture and also the control knobs are correctly aligned on their splines  Good Luck  Peter Posted by Peter Martin 03/05/2016 19:22:32