Not so much like a buzzing for me fingerman. I mean the whole ventilation system is staying on. Eg: When the engine is off and I turn the blower controls to 1,2,3 or 4 the blower motor still works as normal, eventhough the engine is off!

Fingerman, as far as I know, there is a little fan intergrated into the HVAC system that gets clogged up with dust and eventually jams, causing a buzzing cos it cannot move. You will have to remove the HVAC controls and dis - assemble the fan bit off the back and clean it out. It will be behind the small grill just above the Right temperature control knob.

Still does not explain why my blower motor does not turn off...

BeemaBoy

Sorry, meant to give you the link to Realoem.com to show you what the fan looks like...see below...number 4...

http://www.realoem.com/bmw/showparts.do?model=HD62&mospid=47375&btnr=64_0566&hg=64&fg=20 - http://www.realoem.com/bmw/showparts.do?model=HD62&mospi d=47375&btnr=64_0566&hg=64&fg=20

BeemaBoy

simonyo242sw wrote: i've got a e39 and mine does the same but only when the engines warm, had a look in manual it said this was a feature to keep the cabin warm when the engine is turned off.

the REST button on the climate control panel (if fitted) controls this feature

the REST button on the climate control panel (if fitted) controls this feature

[/QUOTE]

yep thats the 1

Was this REST button fitted on the E34??? And if so, how the hell do I turn it off?!

BeemaBoy

Well, I have replaced the Final Stage Resisitor and it has not helped. The ventilation system still stays on and the battery is drained within 2 days when the car is standing .

What is it with BMW's and their electrical problems???

Resolder the IHKA control module. Some of the old solderings or IC's are not good. The heater control module sits behind the center colsole. See my other posting on this. http://bmwe32.masscom.net/johan/ihka/ihka.html - http://bmwe32.masscom.net/johan/ihka/ihka.html  

Hey shogun

I have the older IHKR system, not IHKA. My one has the knobs that you turn, and no AUTO function. Is their still a control module for this older one???

Many Thanks

BB

IHKR is not the older system, but the cheaper system = not fully automatic. So you also have a different control panel too. IHKR of course also has a control module, but it looks a bit different. I only have a very detailed instruction in German language with 'only' 72 pages

No need that you understand all German, but there are both systems shown, as it shows the conversion from IHKR to IHKA. On page 16 pic 21 for example you see the different control modules.

http://www.gunnar525.de/screwings/ihkr-ihka_umbau.pdf - http://www.gunnar525.de/screwings/ihkr-ihka_umbau.pdf

But in general the probs are the same. Good Luck

Some general info on IHKA

There are several common problems, from most to least common:

1 - Failure of the heater valve assembly

2 - Failure of the solder joints of the two power resistors on the PC Board inside the IHKA Control Module.

3 - Failure of the microswitch inside control head. This is the one on the drivers' side thumb wheel that clicks when you move the wheel to the full cold position.

Some background on how the system works ... by default without any power the heater valves are open. So if you are in Norway in the winter and the system fails, you will have heat and will not freeze to death. How thoughtful.

There are three pins on the heater valves. The middle one should have +12 volts all the time with the key on or engine running. It is not always enough to measure the voltage alone. This signal comes through the microswitch in 3 above. It is possible that a dirty switch could stil show 12 volts with no current flow under load. Better to measure the current draw, should be around 2-3 amps if I recall correctly.

You can also check the continuity of the switch, remove the control panel. There is a small 2 pin connector on the back. There should be close to zero ohms in all but the hottest setting. Full heat is acheived by removing the +12 volts from the heater valves.

The ground signal(s) to close the heater valves comes through the two resistors (40 ohms or so if I remember correctly) in the IHKA control unit. Due to the high current and related heat, the solder joints fail. Many times resoldering these connections will solve the problem. However, I have had some where I've had to replace the control units.

To test the heater valves, you can try (at your own risk all usual disclaimers apply) removing the connector and jumping +12v to the middle pin, and grounding the other two pins with a jumper. (might want to check the resistance first, if either of the solenoids is shorted this is not a good idea. Resistance should be +/- 13 ohms or so).

If the heater valves are working ok, then doing this should shut the heat off.

LMK if you have any questions about how to troubleshoot the system. I still don't fully understand it and its operation, but probably understand it better than most.

Hi Shogun

Thanks sooooo much for the .pdf, really useful pics even though my German is a little rusty !

Unfortunately, as I am only 21 right now, money is always as short supply and the Bently manual is a little more than I am willing to spend on a book right now.

If I can be so bold as to ask another question... In the .pdf you gave me, on page 59, relating to pics 113 and 114, they are talking about a IHKR relay. If this relay was faulty, would this not give the problems that I have listed above? Do you by any chance know where the relay's they are talking about are. I think they talk about an orange relay behind the speaker kick panel??? What are your thoughts on this???

Many, many thanks Shogun

BB

Here is something for you to download which will answer all your questions

http://www.eden.rutgers.edu/~szwarc/e34/ - http://www.eden.rutgers.edu/~szwarc/e34/

BeemaBoy wrote: Hi Shogun Thanks sooooo much for the .pdf, really useful pics even though my German is a little rusty ! Unfortunately, as I am only 21 right now, money is always as short supply and the Bently manual is a little more than I am willing to spend on a book right now. If I can be so bold as to ask another question... In the .pdf you gave me, on page 59, relating to pics 113 and 114, they are talking about a IHKR relay. If this relay was faulty, would this not give the problems that I have listed above? Do you by any chance know where the relay's they are talking about are. I think they talk about an orange relay behind the speaker kick panel??? What are your thoughts on this??? Many, many thanks Shogun BB

You can download the bently manual from here. Just rightclick and save target as.. Its a big ish download so be paitent.

http://www.eden.rutgers.edu/~szwarc/e34/Bentley_BMW_5-Series_Service_Manual.pdf - http://www.eden.rutgers.edu/~szwarc/e34/Bentley_BMW_5-Series _Service_Manual.pdf

Cheers

Mick

Hey Guys

Thought I would bring this thread back to life being as I have got the problem sorted. Just to recap, when I pulled the key out of the ignition and locked the car, the ventilation system would not turn off and neither would the radio. It has been booked into the auto electricicans place for about 4 hours and he has tracked the problem down to a huge melted lump of cables below the fuse box on the side of the Firewall. He has told me that since cutting and re-wiring this, the drain on the battery is near to zero as it can be and that the car properly shuts down when I take the key our of the ignition.

I tell you, wiring problems on BMW's are as common as muck!!!

Just happy that the battery will not drain anymore , and strand me 40 minutes from any help...

Cheers

BB