How to replace a blown bulb in the heater control panel

[oldnell]

Disclaimer:
This worked for me. Your mileage may vary. I didn't break anything when I did this, but that does not mean you won't! Proceed at your own risk.

If your car is still under warranty it makes no sense to do this as a DIY job. This has to be one of the most fiddly bulb replacements ever. Similarly, if you're short of time, patience or skills, get someone else to do it.

I believe the following applies to the first generation Mini -- R50, R52 and R53 -- with no air conditioning or with manual air conditioning. The auto air conditioning panel uses LEDs, so you won't get this problem.

In this post, I will refer to the following parts as the "heater control panel".

Air conditioning control
RealOEM.COM * BMW R50 One 1.6i AIR CONDITIONING CONTROL

Heater control
RealOEM.COM * BMW R50 One 1.6i HEATER CONTROL

Symptom:
Exactly half of the illumination on the heater control panel fails.

Likely problem:
A bulb has blown. This panel is illuminated by just two bulbs. When one fails, half of the panel no longer illuminates.

You will need:

• Two replacement clear bulbs of type 509T. These are available from Halfords, who sell their own branded bulb and one by Bosch. I chose the Bosch bulb, which was fine but did not fit as nicely as the original Mini part. Why two bulbs? You're going to be spending hours doing this job, so you may as well replace both bulbs while you're there. Also, there could be a slight variation in brightness between the existing good bulb and the new one. These bulbs are around £2 each.
• Torx screwdrivers (T40 and T20)
• #2 Phillips screwdriver.
• A fairly wide flat-blade screwdriver.
• Small hands.
• Plenty of time and patience.

Follow the instructions in the following link to remove the knee bolster and dash downtubes, and then follow the section on removing the stereo head unit.
http://www.mini2.com/forum/faq.php?f...aq_faq_removal

1. Remove the torx screws
   Remove the six torx screws on the front of the pillars. The bottom two hold the toggle switch panel in place, and the top four hold in the stereo and the heater control panel.
   
2. Remove the toggle switch panel.
   It is preferable to remove the panel entirely to avoid the risk of scratching it, but I couldn't work out how to remove the electrical connector.

Removing the heater control unit.

1. The first step is to set the blower control to setting 4. This will help ensure you don't make the same mistake I did (see later).
   
2. The heater control unit is held in place by two white clips. Once the securing torx screws are undone, they are very easy to unclip. The unit pushes inwards and is removed by pushing the right hand side in first, rotating and then pulling the unit out through its own opening. However, you will first need to remove the connectors.
   
   The heater control unit has two mechanical cable controls (a bowden cable like those for a bicycle's brakes to control the temperature and a shaft to control the direction) and two electrical connections.
   
3. First remove the wire shaft that controls the blower direction. This cable attaches the back of the heater control panel to the car. It is easiest to remove the end that is fixed to the car first. Rotate the direction control until you can access both sides of the clip.
   
   
   
   Reach in and squeeze the clips together and remove by tugging on the cable with your other hand.
   
   If possible, find the other end of this control cable and remove the clip from the back of the heater control unit. If not, manipulate the cable so that you can complete the next step.
   
4. Push the right hand side of the heater control unit in on itself and rotate forward so that you can access the temperature control connector, taking care not to scratch the fascia (although it seems robust). See the pictures in the next section of the unit on its own to familiarise yourself with the back of the unit and the location of its connectors.
   
   
   
   For reference, the connector looks like this:
   
   
   I had considerable difficulty removing this and relied on brute force, levering it off with a screwdriver. There is a good possibility that there is a gentler and better way.
   
5. Having removed the bowden cable, you can now unplug the black and green electrical connectors. The black one can be wiggled and pulled out. However, since it does not seem to be keyed you need to make a note of its orientation (see picture above, assuming the wire colours are the same on your car as on mine). The green one has a clip which must be lifted and rotated to free the connector. The green cable is keyed, so there's no risk of inserting it the wrong way.
   
   The heater control unit should now be free and may be removed from the car to work on at a table.

Dismantling the heater control unit



At the rear of the unit, you will see the following:

A green socket. This is for the lights and buttons.
A black socket. This is for the fan speed control.
To the left of the picture (right of the car) is the temperature direction control.
To the right of the picture (left of the car) is the temperature control.

1. Undo the catches for the fascia by inserting a wide flat-blade screwdriver and twisting each in turn.
   
   
   
   WARNING! I made reference earlier to having made a mistake. Don't whatever you do turn the blower dial. If you were to turn it back beyond zero while the black fascia is removed you would find that a ball bearing flies out and you would more than likely end up squashing a spring. Two ball bearings and a spring provide the "notchiness" for the blower control. I managed to recover the situation by cutting the spring and stretching it to the required length after spending a considerable amount of time scouring the floor for the missing ball bearing.
   
   You can now see the inside of the unit. The orange paint is what gives the illumination its amber colour. The bulbs are actually clear.
   
   
   
2. Remove the dials.
   
   Remove the three dials by placing a wide flat-blade screwdriver underneath and pulling up.
   
   
   
   You can now see the clear plastic light distributor that carries the light from the bulb to the fascia.
   
   
   
3. Remove the clear plastic light distributor.
   
   You will need to manipulate it around the buttons.
   
   Now you can see the two light bulbs themselves, sitting in their carriers.
   
   
   
4. Remove the circuit board by pulling at the plastic sides and pulling the circuit board up. Take care not to bend the board (although it does seem robust). You may need to pull back one or two of the white clips.
   
   
   
5. Unscrew the bulb carriers and replace both bulbs.
   
6. Test the bulbs.
   At this point, before reassembling everything, plug the green connector into the circuit board and turn on the lights. Both lights should now illuminate.

Reassembly
In the spirit of Haynes manuals, refitting is the reverse of dismantling

While reassembling the heater control unit, be sure that the clear plastic light distributor its nice and level, otherwise some bits of the dash will appear brighter than others.

Test the operation of all the heating and air conditioning controls. Check for hot and cold air. Check the blower operates correctly at all 5 settings (if not, you may have got the black connector the wrong way round). Check that the direction control works at each setting and that the knob rotates properly.

I found on reassembly that it was only blowing at one temperature. I followed the bowden cable back and found that the other end had become disconnected. It was simple to reconnect and is located in the driver's footwell of a right-hand-drive car (see picture below).



When reinserting the shaft for the blower direction, bear in mind that it will only fit in one position due to the keying on the connector.

That's it. I hope this is useful. If it is, please click the "thanks" button below!

Thanks to Dan at work for being photographer for a few of the photos.

Cheers

Oli

[DaFlake]

This is a great write up! Thank you for sharing.

[humanfly]

just yesterday I saw that the right backlight heater bulb has died on my dash

this manual seems perfectly detailed so I`ll try doing things on my own. thanks a lot!
threads like this show that mini2 is truly the best MINI community

[arodzx]

Hey folks- thanks for the information. I had the same problem and my dealer said that there was no part number for those bulbs; he further stated that the entire control unit had to be replaced at almost $500 ! This post allowed me to disassemble the thing but that bulb number didn't correlate to anything over here in the States. The specificaions for the bulbs are 12v, 1.2 w. Furthermore, after taking a trip to another BMW/MINI dealer and going through bins of bulbs, they were able to give me the correct bulb!! That part number (I believe its a BMW part number) is: 63-21-7-167-000. The description is: 905D BULB: 07400. They cost me $3.25 each. I hope this helps somebody!!

[aly_ant]

Great write up just did it, thank you so so much =)

[simonre7]

Thanks for the in depth guide i done it today and it worked a treat!

One word of warning though if you manage to get the toggle switch panel unplugged the heater control panel will not light up until this is plugged back in. i spent half hour figuring this out!

[gknorr]

Thanks so much for this in-depth write-up! I successfully did this today.

I have a few notes that may help others.

First, my symptom was the right and left side of the AC/Heater control unit would randomly go out and back on intermittently with no obvious reason. Although neither of my bulbs were actually blown, the wiring inside the actual bulbs had gone bad.

Also, for those searching for the replacement bulb, a 509T might be listed as a T5. T5 bulbs are much easier to run by when searching, but different bulbs come up as T5 at different vendors. Make sure you look at the picture before buying. I got some "T5" LED bulbs off eBay that fit perfectly - $2 for 4 of them. The LED bulbs work, but they aren't as bright as the regular incandescent bulbs, so I recommend going with incandescent replacements.

Lastly, if you want to test that it's working before putting everything back together, make sure you plug both the AC/heater control unit in AND the toggle switch panel in. The two panels must run on the same circuit and without the toggle panel plugged in you will have an open circuit and think that your new bulbs didn't fix everything when they likely did fix your problem! (I speak from experience...)

Thanks again!

[gknorr]

Little more info. on the light bulbs used for this.

The actual light bulbs pop out of the little black plastic casings. The light bulb size I used as a replacement is a "74" and is commonly available at most auto parts stores. It popped right back into the black casing and everything looks great again!

So, just get two "74" size bulbs for this job, and you'll be set.

[solidsponge]

Nothing is simple with the mini is it? jesus christ, all this to replace bulb. I havent even read it all. For the VW polo (better interior quality) it was this > remove cover, pull out and put in bulb! This is seriously over the top. I will be leaving the bulb blown, more likely to break something else taking it off

[jimaikin]

My lights are out and the fuse panel shows a bunch of different fuses related to what seem to be the instrument panel. F5, F9, F21, F30. I am going to check all mine before I think about tearing the panel apart. Does anyone know which fuse is associated with the climate control panel lights?
Thanks in advance for the help..