Digital climate control fix DIY

[spoonerDee]

I have seen a bunch of threads popping up lately about people having trouble with their climate control and the fan not working, so b4 you spend a ton of money on a new fan try this first.

Problem: climate control is on (never turns off on its own) but fan will only blow at one speed or not blow much air at all.

If the unit itself is cutting on and off (losing power) then its a different problem (a capacitor i believe) which a diy already exsists for.

Solution: Replace the final stage blower moter resistor. Costs vary from 75 dollars to 125 dollars> here is the link to the cheapest one i can find now at 82 dollars. it is listed as the final stage resistor.

http://www.pelicanparts.com/bmw/cata...VENTac_pg3.htm

The manual resistor is only around 25 dollars from pelican parts



Here is how you fix it.

Tools:
Phillips screw driver
Torx 20 driver
10mm socket with extension (maybe)

total time 30-45min

This can work for the manual climate control, your sensor looks different and is located in a slightly different spot and only costs about 30 dollars. There is a specific DIY on Pelican parts for the manual climate control resistor

here is the digital resistor


and here is the manual resistor pack:



Now to take off the driver's side knee bolster. This only requires you to remove two screws, one on the right side of the bolster and one on the left. Using the Phillips screwdriver remove the following screws:



Now remove the speaker (beeper) and foot well light.





this next step might apply to older vehicles, this was not in my car

Using the 10mm socket remove the 3 bolts holding the metal shield. And using the Phillips screwdriver remove the obd2 port.



Now you should be able to see the foot well air duct. Remove it by pulling it.



With everything out of the way you should now be able to see the defective final stage unit. Remove it using the torx-20 screw driver.



Replace it with the new part and before you put everything back turn on your car and test the blower. If everything is ok proceed to put everything back, and enjoy the benefits of having a blower in your car again.

My climate control had been acting up for years then one day the air just stopped flowing. After doing some research i found someone who had done this and to my surprise it solved everything.

So b4 you go and blow $150 to $350 on a new motor which 9 times out of 10 is not needed you can spend $30-$70 and save your self a fortune, allot of work and finally have air again.

[lunarc]

Hey Spooner can you check my post and let me know if this seems to be the same thing you experienced?

http://forums.bimmerforums.com/forum...d.php?t=958740

[spoonerDee]

Hey Spooner can you check my post and let me know if this seems to be the same thing you experienced?

http://forums.bimmerforums.com/forum...d.php?t=958740

some of the problems you are having seem very similar to what i was seeing, with the exception of the A/C turning on randomly. That could be the result of a short somewhere. Id say try swapping the resistor which should fix the fans, then see what happens with the a/c

[mxv1496]

hey spooner, if i can only consistently get the blower motor working by manually spinning the blower motor blade underneath the cowl panel after turning the knob in the on position...is that the blower motor problem or the resistor problem? thanks.

[spoonerDee]

hey spooner, if i can only consistently get the blower motor working by manually spinning the blower motor blade underneath the cowl panel after turning the knob in the on position...is that the blower motor problem or the resistor problem? thanks.

sounds like the motor

[Ramv36]

The blower in my 96 328is stopped working tonight. It was working great early as yesterday and the digital control in the dash was replaced 2 weeks ago when i bought the car. It blows no air regardless of setting.
Could this be the final stage resistor? When i set the digi climate settings i can hear the vents opening and closing when i change it. Yes the vents are open at the vent controls and yes the dash vent settings are correct (heat for heat). Checked all fuses under hood and none are blown.

Anyone know what this is? Thanks for any help!

-Robert M.

[bmwpower007]

The blower in my 96 328is stopped working tonight. It was working great early as yesterday and the digital control in the dash was replaced 2 weeks ago when i bought the car. It blows no air regardless of setting.
Could this be the final stage resistor? When i set the digi climate settings i can hear the vents opening and closing when i change it. Yes the vents are open at the vent controls and yes the dash vent settings are correct (heat for heat). Checked all fuses under hood and none are blown.

Anyone know what this is? Thanks for any help!

-Robert M.

This is the exact problem I am having. The digital climate settings I have for the car doesnt blow hot or any air for that factor. Yesterday it started working the whole day and stop working again. It comes and goes every now and then.

Would the final stage unit correct this problem?

Everything is checked including the fuses and lightings and switches, the valves as stated by you is also working I can hear them. But when I put low or high settings doesnt blow heat at all. Its getting very cold down here and its freezing! 0 degrees Anyone has this problem. It doesnt work on one setting, doesnt work at all. And when it comes back to its senses it starts working normally from low to high settings.

Anyone??

[berkeleyEE]

If your heater fan (blower) has failed at the lower settings, but still works at the max setting, then this is because one or more of the final stage blower resistors is open-circuit. Replacing them is what the Original Poster described. The cause may be the blower is old and the bearings failing and requiring more current to maintain speed. So the resistors that provide the lower speed settings get over-heated and they fail first. So possibly your blower fan is on its last legs.

But if your problem is the Climate Control Unit (heater and A/C) randomly turning off or dim or on, then that's attributed to a specific capacitor on an internal PC board. This website describes how to fix it: www.macadamizer.com/bmwfix.html

In my case, I didn't replace the capacitor. I just touched the two solder pads with my soldering iron (a reflow) and the CCU has worked fine ever since.

Good luck

[bmwpower007]

If your heater fan (blower) has failed at the lower settings, but still works at the max setting, then this is because one or more of the final stage blower resistors is open-circuit. Replacing them is what the Original Poster described. The cause may be the blower is old and the bearings failing and requiring more current to maintain speed. So the resistors that provide the lower speed settings get over-heated and they fail first. So possibly your blower fan is on its last legs.

But if your problem is the Climate Control Unit (heater and A/C) randomly turning off or dim or on, then that's attributed to a specific capacitor on an internal PC board. This website describes how to fix it: www.macadamizer.com/bmwfix.html

In my case, I didn't replace the capacitor. I just touched the two solder pads with my soldering iron (a reflow) and the CCU has worked fine ever since.

Good luck

Well my climate control unit in the dash works fine, all the lights on it are ok, the buttons all work. It doesnt become dim or whatever just works like it should. Its just that when I put on a low settings or any settings, you see the bar even on full power nothing happens. Like it says the bar is full on max, but there is not heat blowing from the vents its like the blower has stopped working or something. At times, sometimes I would start the car and it works.

I think this link you provided is something else im guessing. Is it a pain in the ass to take the blower motor out, any instructions in how to go abouts this.

Do you think that I should find the bushing for this motor and replace it and put it back or just get another used motor, cause dont have money to through now like 150-350 dollars.

[bmwpower007]

sounds like the motor

Hey, I just wanted to know. If the digital climate controls lights up properly and all the functions are ok and working.

My digital climate control works and all the lights and eveything. When I put the fan on high or any settings the motor doesnt blow at all its like its off. At times it comes back and works like normal.

My questions is would a relay cause this problem of the motor working or not? Any ideas? What does the relay do and could it be a cause of it if all the fuses under the hood is ok?

[randomy]

foot well light!

[spoonerDee]

Hey, I just wanted to know. If the digital climate controls lights up properly and all the functions are ok and working.

My digital climate control works and all the lights and eveything. When I put the fan on high or any settings the motor doesnt blow at all its like its off. At times it comes back and works like normal.

My questions is would a relay cause this problem of the motor working or not? Any ideas? What does the relay do and could it be a cause of it if all the fuses under the hood is ok?

if it comes on once in a while then 9 times out of 10 its the final stage resistor.

if it works at only one setting hence you turn it up all the way but air only trickles out, or if you have it low and nothing, then turn it up and it works, then it is the resistor.

for mine when the problem first started the fan would rev up and down but never shut off. then one day (few days b4 my wedding) the motor just cut out completely, no air at all yet all the gauges were lit.

then the next day it came back on but only at the lowest setting no matter what i did. A few more times it cut out completely and would give off no air. it stayed that way the rest of the summer until it started to get cold and i needed to have heat.

I thought initially it might be the capacitor in the climate control unit it self. I asked one of those guys who replaces them on ebay and he said no, most likely the final stage resistor.

So once winter came around and i really needed heat i bought one, installed it and it works beautifully.

Best case scenario for most of you is to start with the resistor Its allot cheaper and easier to replace then the motor it self and most of the time it will solve the problem.

If you do replace the resistor and the motor still does not work then it means the motor is shot as well. Its not a total loss in replacing the resistor as well because they are prone to failure. It is becoming a more common problem as our cars age.

Hope i answered all your questions guys, if you have more just ask or PM me as i don't always get back to every thread. Best of luck to you all.

[spoonerDee]

also a little background on what the final stage resistor does:

The blower motor fan really only has one speed. The final stage resistor actually controls the speed of the motor from low all the way to high by limiting how much power goes to the motor (or something of the sort).

With out the resistor the motor would only blow on high, the resistor allows it to slow down.

Starting to get the picture? So if that goes, 99% of the time you get one speed, some times none at all. Thats why it will cut our or only give you high or low.

[bmwpower007]

[quote=spoonerDee;14571125]if it comes on once in a while then 9 times out of 10 its the final stage resistor.
quote]


Could a relay in the fuse box cause this problem too?? Cause it really doesnt make sense to me at all. If the motor ends up working and blowing air all the fan speed works like normally, and then it just stops working completely with no low settings mid or high settings. Its like something is stopping it from functioning normally.

[spoonerDee]

[quote=bmwmpower88;14571252]

if it comes on once in a while then 9 times out of 10 its the final stage resistor.
quote]


Could a relay in the fuse box cause this problem too?? Cause it really doesnt make sense to me at all. If the motor ends up working and blowing air all the fan speed works like normally, and then it just stops working completely with no low settings mid or high settings. Its like something is stopping it from functioning normally.

that would be the final stage resistor.

As i said with mine, it would work fine and great then not at all then at one speed then not at all then again fine. then it finally died after playing that game for several months.

If a fuse went it would not work at all, if there was a short it would flicker on and off and eventually blow a fuse.

[bmwpower007]

[quote=spoonerDee;14571334]

that would be the final stage resistor.

As i said with mine, it would work fine and great then not at all then at one speed then not at all then again fine. then it finally died after playing that game for several months.

If a fuse went it would not work at all, if there was a short it would flicker on and off and eventually blow a fuse.

Lol.. I love it the way you said "that game" lol.. its like you know work you son of bitch lol .. Well I would love to order a new one, but right now at this stage Im going to get whatever I can get my hands on. Cause its like -5 here degrees freezing.. and the windows are fogging up since there is no heat Maybe ill replace it from a scrap yard.. and then order the new one as its going to take time to get here.

[spoonerDee]

when i ordered mine i had it within like 3-4 days. But when its cold, any way you can get it faster, do it lol. Totally sucks when your freezing and your windshield is a sheet of ice inside and out.

best of luck to you all

[bimmer335i07]

Great DIY!

Too bad I didn't see your post earlier. It took me a couple of minutes to locate the blower resistor. lol! And for the manual climate control, it's just plug and play, no need for an allen key.

I just installed my new blower resistor and now all the fan speeds work. Before only 3 & 4 worked.

Thanks again to the members of bimmerforums.com for helping me out.