hot air
- Thread starter phil.a
- Start date
Z
zedonist
Guest
Good chance it's linked to the aircon not working, if everything else is working fine.
did you go through all your fuses? check the back of the dials, not sure how it works in bmw but there might be a rheostat involved which might be just gone. if you can get your hands on another control unit and swap out to see if that works.... hopefully its just a fuse 
Z
zedonist
Guest
It could be a broken Bowden cable to the regulator flap?
Z
zedonist
Guest
Well both heater and air con systems are controlled by flaps, which control the input of air from outside or inside the car, I think on modern cars it is called the circulation for inside sir, anyway this is the difference between cold and hot air, on our cars, this is done by a wire attached to a flap and the dial the turn, if the wire or mechanism is broken, the flap will not turn.
A lot of the Z3 is taken from "older" BMWs, so tend to have fairly basic operation. Cables, pulleys and mechanical stuff galore. Probably just as well because electrical stuff tends to be harder to fix...
Z
zedonist
Guest
Well Z3 are not modern cars they first came out in 1995, nearly 20 years ago, the design other than exterior did not change, modern cars have servo motors on the flaps, the Z3 has cables, which us good because they are cheaper, if that is what is wrong..........
could well be as there is no feel to the heater knob thats why i thought it might be electric, will have to find some time between doing the kitchen up before winter comes on, better hot than cold this time of year,
Are there any vacuum operated controls on the heater flaps?
not sure were to look busy in the house at the moment as soon as i get some time will check it out, but from what as been said so far it may be a cable as there is no resistance at the control knob
Z
zedonist
Guest
No Tony, just a cable:
Z
zedonist
Guest
You may be able to do it without removing the centre console, but it will be extremely tight, using the side access panels and the radio slot, and for the pain, IMHO, it's not much extra just to remove the console, it's then just like replacing a bicycle brake cable.
If of course you fancy scraping those knuckles, or if you have exceptionally small hands, this article will show you how to get at the back of the heater controls through the radio aperture.
https://zroadster.org/articles/bmw-z3-replacing-heater-control-bulbs.65/
https://zroadster.org/articles/bmw-z3-replacing-heater-control-bulbs.65/
It is possible that your heater valve does not close when you turn the temperature controller to the blue zone. When the controller is turned to the maximum cold setting (blue zone) full voltage is applied to the heater valve to close. Your problem could be due to a blown fuse, faulty controller, or a loose earth connection. I have a similar problem with my car that the heater does not work at all even with the controller in maximum heat (red zone) with the fan operating at the maximum setting. I removed the supply plug to the heater valve with controller at the blue zone and checked the voltage with a multimeter and measured zero voltage. If the system was working correctly the meter should have read 12.5V. Mine appears to be due to two problems. Heater valve stuck closed combined with a faulty controller or loose earth connection. Any comments or ideas would be welcome.
Z
zedonist
Guest
Good call Aussie, I would check the simple things first though as that valve is a bit expensive, but logic would suggest if the cables are ok, the fuses are ok, the wiring to the valve is ok, it could be the valve.
I have checked the main fuses feeding the valve and they are ok. My air conditioner works well and the fan blows air through all the vents including the windscreen vents indicating that the dampers operate as required. When the controller is turned from blue to red zone and back the valve should open and close and if you listen carefully you should hear the valve operation. The heater valve on my car definitely does not operate and the only items remaining to be checked is an inline fuse to the valve behind the center console and the earth connection at the passenger side foot well. I will check these and get back.