Heater Control - how does it work?

Need technical Q/A then you're in the right place

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Motorhole
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Post Thu Jun 20, 2013 3:32 pm

Got my dash back in, reconnected all the heater vent cables no prob and plugged in the heater temp switch plug. But the cable that goes to the heater temp switch - what does this do? Mine is really, really stiff and takes some real effort to move back/forth. Also, unlike the the other cables, I can't find somewhere where the outer cable clips into place? Only where the ring slides onto the heater control. Worked fine before I took everything to pieces, what's the deal?
milescook
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Post Thu Jun 20, 2013 4:16 pm

Subscribed as I have this exact problem after 're fitting mine'. Also mine only seems to blow hot...
The story so far... http://www.cookracing.co.uk/

Also please help the race budget by watching some videos :) https://www.youtube.com/cookracinguk
Motorhole
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Post Sat Jun 22, 2013 10:30 am

Bump?
daimlerman
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Post Sat Jun 22, 2013 1:38 pm

No cable to the heater temperature control,it's worked by electrikery....
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Motorhole
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Post Sat Jun 22, 2013 2:31 pm

Thanks for your response Malcolm. I have plugged in the heater control and I'm aware the coolant flow valve is electrically operated, but there is definitely a 4th cable and this diagram at least suggests it attaches to the arm on the heater control knob? The way the arm moves when you turn the knob also suggests that a cable attaches - although I don't know what it does.

http://bmwfans.info/parts/catalog/E30/2 ... egulation/

I'm guessing that thumb screw and clip suggest the cable is also mounted somewhere else, but can't see where.
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Brianmoooore
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Post Sat Jun 22, 2013 2:50 pm

Heater temperature on 99.99% of E30s is controlled almost entirely by a bowden cable that moves a blender flap in the heater box.
The 0.01% that aren't are those with climate control, and the electric cable and valve are only there to ensure the heater is truly cold when the temperature knob is in the last few degrees of being turned to full cold.
Adjusting the cable is a bit on the fiddly side, but basically you set it so that the flap moves throughout its full range at the same time as the knob turns through its full range. I.E. Ensure that the knob hits its stops before the flap does.
You can see the other end of the cable by removing the panel above the driver's knees.
Motorhole
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Post Wed Jun 26, 2013 8:53 pm

Bump:

I'm still unsure how the cable attaches to the heater control knob - it was 3 years ago when I took it to pieces and (stupidly) I didn't take any photos. Any pointers or photos as to how it hooks up would be ace.
clipper
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Post Wed Jun 26, 2013 9:04 pm

IIRC the outer cable, the sheath has a metal tip which locates in a pinch clip that is tightened with a small screw.
These are sensations as hard to forget as they are to ignore.....
Motorhole
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Post Thu Jun 27, 2013 2:33 pm

clipper wrote:IIRC the outer cable, the sheath has a metal tip which locates in a pinch clip that is tightened with a small screw.
Yeah, this is the case for the 3 cables that link to the sliders for directing air. But the heater control appears to be different? I can find anywhere to 'pinch' the cable.
milescook
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Post Mon Jan 06, 2014 10:10 pm

Bit of thread necromancy here... finally had a really good look at mine and I can see that turning back to cold doesn't push the cable back though I can move the rocker with my fingers. Any joy mh?
The story so far... http://www.cookracing.co.uk/

Also please help the race budget by watching some videos :) https://www.youtube.com/cookracinguk