| Last night I finished the installation of the refurbished W124 instrument cluster. I’m really happy with it, and its really lifted the car. I ended up installing it as part of my failed attempt to change the centre vent. Even after changing the bulb, the vent illumination was not working. I realized that it must require the instrument cluster to be plugged in. This proved to be the case, and also fixed the illumination for the outside temperature gauge. Before I re-installed the cluster, I added more ATF to the speedometer cable. This is an attempt to lubricate it and stop the speedometer needle bouncing around at low speed. I then plugged in all the electrical connections. Most of them had plenty of slack, so this part of the job was quite easy. Re-attaching the speedometer cable is more fiddly as there is minimal slack. I didn’t push the cluster all the way in and did a test drive around the industrial complex. It was soon apparent that the bulb that illuminates the left hand side had blown. I had one left in my box of bulbs, so I quickly swapped it over. If you own these cars, its really handy to keep spares like this on hand. On the less positive side, I can’t say that the ATF has really helped my speedometer needle a great deal. It is improved, but not by very much. It was worth a try. 
Given that you are sitting in front of the instrument cluster the whole time you are driving the car, I think is a very worthwhile improvement. I find these sort of projects really make a big difference. My refurbished W124 instrument cluster wasn’t all that expensive and only a few hours work. It is especially apparent when compared to how it was. 
One of the items on my todo list for the 300TE was to replace the W124 centre vent. A couple of the slats were broken, so I could not direct the air, and the open/close control was not working either. The open/close control is especially important in winter, as heat doesn’t come out of the centre. I was told that the RHD part is different to the LHD part, so when I saw a reasonable deal on the RHD part, I purchased it. The part number (at least for my car) for the W124 centre vent is A124 830 08 54. From looking at the new part, it had screw holes on both sides, so I assumed that it would require the instrument cluster to be removed. Turns out that the right screw hole is not used, so the vent can be removed without removing the instrument cluster. On seeing that, I looked in the EPC, and actually I don’t think the RHD and LHD parts are different. And I think that extra hole proves it. 
There are four things holding the vent in. A screw on the left hand side which is accessible with the glove box door open. Then there is a small bolt holding the vent onto the flap behind it. This is removed with an Allen key, 4mm if I recall. It is accessed from the right hand side of the vent, near the centre (pictured above). Finally there are two clips also on the right hand side of the vent. One of mine was broken, but the other I could get up with a long thin screwdriver. It helps to have the new part on hand to see where they are. Finally, there is a small bulb that fits into a slot in the back at the bottom centre. This was blown on my car. 
I was able to get the old vent out pretty easily. And generally putting the new vent in is the opposite of removal. There were two slightly tricky aspects. The first involved changing the bulb. I bought a bag of these dash bulbs about 10 years ago when I had my black 560SEC. I used the final one one for this repair. Firstly, I couldn’t get the bulb to work at all. Then I noticed that none of the dash lights were working. I realized that the instrument cluster must be installed and plugged for the dash lights to work. This also explained why the light for the outside temperature gauge wasn’t working. I re-installed the instrument cluster, and then found that while the bulb wouldn’t work when fully inserted, being out about 1mm had it illuminated. 
It took a few goes to get the bulb holder into its socket, and the wire fed into the wire holder at the bottom of the vent. On the first few tries, the bulb pushed all the way in and stopped working. Eventually I had it in and was greeted with a properly illuminated dash. The next part was to push the vent in. That was trivial. Lining up the allen bolt with the plastic connection for the flap was harder, but I found it easiest with the flap and vent wheel in the closed position. It was all going well, until I tightened that bolt too far and snapped something. I’m pretty sure its the plastic piece that goes onto the flap. This is really frustrating as fixing this was the primary reason I was installing the new vent. I can’t see that plastic bit as a separate part, so I suspect I will need to get a flap from a wrecked car that has a good plastic part and transfer it. I’m really annoyed with myself, I was being careless screwing in that bolt. I still have a slight improvement, as the bulb works, and I can at least direct the air left and right. But the main reason why I spent about $250 and an hour of my time is a big fail. In a previous article I had been undertaking a 300TE speaker upgrade. I started with the rears which were very simple. Next was the fronts. As I outlined in the first part, the W124 uses an odd size and mounting system for the front speakers. They are 12cm and use these clips on the side rather than the normal mounting ears. I guess this system was used in a few European cars of the era, as there are still a couple of manufacturers who offer speakers like these. 
I went with the Crunch DSX120, in a kit for the S124 that included adaptors for the Becker plugs. The picture above shows the underside of the speaker and the mounting clips. For some reason the speaker connections are hiding under the magnet and I had to bend them back to put the supplied adaptors on. The supplied adaptors were pretty poor quality. The positive terminal fit ok, but the negative terminal was too large and needed adjustment with pliers to make them work. However, to mount the new speakers, first had to remove the old. The grilles are easy to remove once you know how. The thin strip to the side of the grille just clips into place. It can be removed with a trim removal tool or even a flathead screwdriver. Once removed, there are two screws that hold down the inside of the grille, with the outside held down by two plastic tabs and the A pillar trim. 
Once I had the trim off, I was confronted with some small speakers that had been poorly mounted in the holes. At least they had not cut the hole any larger. No wonder they rattled and sounded terrible.  The previous installer had soldered them to the Becker wires, which seemed a lot of work when fitting the wrong sized speakers. As nothing was cut, it was a simple matter of just clipping the new speakers into the factory speaker holes. They fit perfectly.
 I tested the speakers before I refitted the grilles. They sounded a lot better. No more rattling and buzzing from the passengers side. The extra size also added more depth.
Once tested, I put the grilles back on and my 300TE speaker upgrade was complete. I am pretty happy with how it sounds with the original Becker. Unlike in the 560SEC I am not running a modern amplifier. Given the size of the rear speakers, I don’t think its necessary. This has been a quick and simple upgrade that sounds a lot better. And now with the factory grilles installed, it is invisible. Doing the front speaker upgrade was also the impetus for me to refurbish my instrument cluster, as I could push it out from the speaker hole. Today was the third annual Youngtimer Sacco day. This is an event run by the Mercedes-Benz club to celebrate the cars of the legendary designer, Bruno Sacco. As with the last two, the event was held at HARS. HARS is an aviation museum located at Shellharbour Airport in Albion Park NSW. 
The event is focused on the cars designed by Bruno Sacco, but other cars could attend. Sacco was lead designer for Mercedes-Benz from 1975 to 1999. His era covers a number of key models in Mercedes-Benz history such as the W126, W201, W124, R129, R230 and more. Sacco also contributed to the W123, although mostly under the direction of Fredrich Geiger. I had planned to take my 1987 560SEL. I own three Sacco cars, the 560SEL, my 1987 560SEC and my 1990 300TE. The 300TE was ruled out as the instrument cluster is still out, as is the centre AC vent. I’m taking the SEC down to Melbourne later in the week, so I thought I would take the SEL. However, after driving out of a multi-storey parking lot on Friday night, the drivers window failed to go back up. I assume the plastic slide in the window regulator is broken or jammed. That ruled it out and I took the SEC instead. The SEC went well, and the wheel alignment and balance seems to have fixed my wheel wobble issue, although I still have some vibration at low speed turning. 
As with the 2020 event, we started at Tynan’s Mercedes-Benz dealership. We then took the Grand Pacific drive though the Royal National Park before ending up at HARS. Unlike the last two events, we could not drive the cars onto the apron. Some idiot drove a BMW M-car at high speed on an active runway, causing cars to be banned. I hate these knee-jerk rules, they should have just thrown the book at the offender. The drive through the national park was good as always, and the cyclist menace was not as bad as normal. HARS is well worth a visit – they had multiple aircraft flying, and we could take a tour of the Super Constellation and the Boeing 747. I took my three kids and they all enjoyed HARS. After a couple of hours at HARS, we took a very enjoyable drive over Macquarie Pass to Moss Vale for lunch. This was the same place we had lunch in 2020. I understand there were more than 30 cars on the day. This time the W124 was the clear majority. In the first year, the W126 was king of the hill, especially the 420SEL. There were probably as many 420SELs as there were cars today. Although I am a big fan of the designs of Bruno Sacco, my favourite car on the day was the W111 280SE 3.5 cabriolet, a design of Paul Bracq. The day was really good, and an improvement over 2021. In 2021 the weather was rather poor, and we didn’t do the second drive for lunch. I’m glad that was brought back. We didn’t top 2020 as that event was huge and we had access to the apron to show off the cars. I think that was what was missing this time – we didn’t have the showcase of all the Sacco designs lined up. I certainly enjoyed the day and Youngtimer Sacco day remains one of the premier events on the MBCNSW calendar. I wasn’t very happy with the sound from my 300TE. The front passengers speaker rattled badly and the sound wasn’t the best. As I’m taking the car on a road trip in January, I wanted better sound. I’ve already put the Becker 1402 back in, so all I needed was some decent speakers. In researching what was possible, options were not extensive for the S124. The front speakers are both an unusual size (12cm) and an unusual mounting system. The rears are are a more common 10cm size, but mounted in the door handles. I personally don’t think much of the speaker setup in the car. There is room for some larger speakers in the front, and the door handle speakers are just silly. It would have been possible to come up with a much better way to mount door speakers in a much larger size. Certainly in 1990, the W126 in some markets (Not Australia) already had much better door mounted speakers. 
Given these idiosyncrasies, I there were not a lot of options for the car. I found a German car audio store that was selling a kit for the S124 that included the four speakers and adaptors for the Becker plugs. I bought this, and also the correct speakers for my 560SEC to combine shipping. These were the Crunch speakers pictured above. I started from the rear. The rear speaker grilles are very fragile, and its likely ham fisted speaker installers have damaged them over the years. There is a screw on the underside, and then the grille lifts up. Unfortunately some owners have put screws in the top which is highly unsightly.  My car wasn’t that bad, but the clips on the top of the drivers side rear were broken off, so some kind of glue was holding them in. Removal of the cover revealed a decent looking Alpine speaker. I prefer to have all four speakers in a car the same make and model family, so I still changed them.
The new Crunch speakers went in quite easily. I didn’t need to use the adaptors, as the Alpines had normal speaker plugs. It was fairly trivial to plug them in and put the grilles back on. The first part of my 300TE speaker upgrade only took about 30 minutes to do. I thought I had photographed the new speakers in place, but looks like I didn’t. At this stage, its hard to determine the impact as the rears are less important than the fronts. I had previously replaced the front speakers in my 1987 560SEC. Now it was time to look at the rears. As I outlined in the article about the front speakers, I am replacing the W126 rear speakers with Crunch 16.5cm speakers. These speakers should fit into the factory brackets and underneath the factory grilles. Changing the rears in the second generation W126 is a bit more of a fiddly job. For starters the factory grilles are now very brittle. Not only are they over 35 years old, but the Australian sun is not kind to plastics. It is quite common for them to break when removed. The best way to ensure this does not happen is to remove the seats first. The grilles have to slide towards the front of the car, and the top of the rear seat is in the way of that. Despite having owned three 560SEC’s in my life, I had never removed the rear seat. I assumed it was like the C107 or W111 coupe, where getting the rear seat out is like wrestling with a gorilla. However, that is not the case in the SEC. The left and right sections are removed separately, making it quite easy to get them out. As with the saloon, the bottom cushion is removed by pressing the red tabs, and then the backrest lifts off ‘hooks’. It took me a matter of minutes to get the seats out. While they were out, it was a good opportunity to clean them and apply leather conditioner. While I regularly clean and condition the seats in the car, it was amazing how much better a job I could do having them out. It was almost worth doing this job just to force me to remove the seats and clean them. 
Once the seats were out, the speaker grilles could be removed. They slide towards the front of the car. It is vital to be very gentle with them. There are various hooks that are easily broken off. The hardest one to get out is actually the front one. Normally what happens is that it also pulls out its receptacle from the parcel shelf. Once I got the grilles out, I was shocked to find that the car still had the original factory speakers. Still with the original MB part number on them, made in West Germany. They sounded better than the more modern Pioneers I removed from the front. It seems incredible that somebody would go to the trouble of rewiring the car for the speakers, fit new front speakers, fit a new head unit and leave the old rear speakers alone. As the car had been rewired to remove the fader, the becker plus were no longer there.  The series 1 W126 had the same size speakers front and rear. To fit larger speakers in the series 2 cars, the factory came up with these angled brackets to fit a 16.5cm speaker. The brackets are held in with two screws towards the front of the car. Once those are out, the unit pulls towards the front of the car and can be lifted out.
The factory speakers are glued to that bracket. Given their age, its fairly easy to pry them off the brackets with a screwdriver. Instead of gluing my new W126 rear speakers on, I used double sided tape. 
The Crunch speakers fit perfectly in the brackets. The speaker is actually deeper than the bracket, but that is ok, as there is a hole in the rear parcel shelf for them to protrude through.  Once mounted, the Crunch speakers are slightly taller than the old factory ones were. They still fit into the hole in the parcel shelf and the factory cover still fits on there quite well.
 In the picture above, you’ll see the square hole in the parcel sheft to the front of the speaker. A receptacle for one of the hooks in the speaker grille goes in there. In both cases for me, the receptacle came off with the grille. It is much easier to fit the grille if you remove the receptacle from the grille and put it back where it goes. I found this out when doing the second speaker.
But before I put the grilles on I tested the quality of the sound, and I was happy with it. Its not perfect, but its a huge improvement on what I had before. I feel like I have a system that looks like a factory setup, but sounds better. I also have much nicer and cleaner rear seats. I’ll have a long road trip to decide how good this system really is. In testing the setup, It also sounds heaps better if the EQ function on the iPhone is disabled. 
I’m planning to drive my 560SEC down to Melbourne in a few weeks. I’m going see the Mercedes Benz Club of Victoria concours and attend a tech day on electrical troubleshooting. A drive like this meant attending to a few things I had on my to do list for the car. One of them was to replace the W126 drag link. It was supposed to be replaced at the same time as the tie rods and idler bushing were done. Unfortunately, I had bought the wrong part. I should have realized but the left hand drive part is different to the right hand drive part. The part number for the RHD drag link is 126 460 09 05. The other thing I wanted to do was check the balance of my front wheels, as I had a wobble on the way down to Canberra for the ACT concours. I figured it made sense to do the drag link first, then send the car in for an alignment and to check the wheel balance. The drag link is quite an easy job to do with a hoist and the tool to pop off the ball joints.  As it turns out, this would be the last job I would do on the hoist for now. Once I finished it, I started putting the 300TE and noticed a growing puddle of hydraulic fluid on the ground. I quickly got the car down. I’ll need to get the hoist serviced.
With the new W126 drag link in, the groaning/vibration I was getting from the steering at low speed was almost completely gone. The old drag link looked like it had been on for a long time. Certainly the tie rods were probably from the car’s time in the UK, as the bolts were rusty. I took the car to the alignment shop. They found it was quite badly out of alignment, and that the front wheels didn’t have enough weight on them. I haven’t been onto a motorway since, but a short burst of speed made the car feel a lot better.  The other thing I di while I was working on the car was fit a BM2 Battery Monitor. I’ve got these on a few other cars. It allows me to monitor the health of the battery from bluetooth.
I’m taking my 560SEC on a long road trip in a couple of weeks. I’ve never really been especially happy with the sound from the speakers, particularly from midrange tones. Before I took the car on a long trip, I wanted to upgrade the speakers. 
I am also doing a similar project on my 300TE. On that car, one of the front speakers is damaged and makes a rattling sound. The W124 speakers are harder to find than for the W126. The front speakers on a W124 use an odd mounting system, and the rears have minimal clearance. There was an audio store in Germany that sold a kit for the S124, and also carried speakers that should fit into the second generation W126. It made sense to buy them all at once, as shipping from Germany is very expensive these days. Based on that, I ordered four sets. I prefer to keep all four speakers from the same manufacturer (and ideally the same range) in a car. The speakers for the W126 were 10x15cm for the front and 16.5cm at the rear. The factory front speaker in the W126 is actually a small round speaker in an oval housing. These can be replaced by oval speakers. They also came with adaptors for the Becker plug system. 
When I removed the grilles in the 560SEC, I found a set of old Pioneer 4×6″ speakers in there. They looked like they were about 20 years old or so. The Becker plugs were long gone, so it was quite easy to use the standard speaker plugs for the new crunch speakers. On comparing them, the Crunch speakers had a far larger magnet, and it was quite a tight fit to get that magnet through the speaker opening. The speakers don’t sit quite flush due to the large magnet size, but there is just enough room to install the speaker and cover it with the factory grille. 
The new speakers sound a lot better. It’s never going to be perfect as I’m playing music through an FM transmitter, but they do make a big difference. On the 560SEC, I am using a Becker 1402, coupled with the factory line out module to use an external amplifier. Next step is the rears, which are far more fiddly to install on the W126. 
In this series I am refurbishing my W124 instrument cluster. In the first part, I removed the cluster and lubricated the speedo cable. For the second part, I repaired the W124 outside temperature display. Now I am focused on my instrument cluster which is afflicted with the dreaded white spot disease. While I was in the UK for work in January, I purchased a good used W124 instrument cluster housing. My plan was to transfer my instruments and electronics to that new housing. The actual gauge faces were in good condition. It’s been on my to do list ever since then. I didn’t know about the bitumen stuff that covered my cluster back then, but this has the added benefit of fixing that too. The new housing is almost perfect. It has no white spotting, and the glass is in great shape. It still has the rubber blocks that help the cluster stay in too. The only slight imperfection is there is a little bit of melting around where the dash lights go. A previous owner of this cluster probably used the wrong bulbs. It is also ever so slightly different, with a ridge at the bottom. 
I had already removed the cluster and the outside temperature display which is the first step. Unlike on the W126, where its easier to remove the instruments individually, I found on the W124, it sort of all has to be done together. I first removed all the screws that hold in the speedometer and rheostat. However, this didn’t really want to come out until I removed the screws that hold in the left and right circuit board and instruments. There are two on each side. For example the little circuit board on the top left is underneath the silver housing for the clock and tacho. 
A lot of people at this point would paint the needles on their instruments. I personally don’t like to do this, as the needles should be the same colour as the max RPM marks and crosshatched section on the speedo face. My hand is not steady enough to repaint those, and freshly painted needles just show up those sections unless they are done too. Getting the instruments in the housing was not hard, just a bit fiddly. I found I had to start by clicking in the small circuit board above the clock/tacho and then slowly guiding in the other instruments. The other thing I had to change was the backing for the warning lights. This cluster had obviously come out of an Airbag car. Its a simple matter of using tweezers to pull out the backing strip and put in the correct one for my car. These backing strips vary quite a lot, depending on the car they came out of. Interesting that the font changed a bit. 
Just a simple thing like changing the W124 instrument cluster housing has made a huge difference. As it sits in front of you as you drive the car, I think it’s a worthwhile improvement. The white spot is gone, the glass is clear and I can see my instruments properly. When I couple this with the repaired outside temperature LCD, its going to be a big improvement. The final step for this process is going to be reinstalling and testing the instrument cluster to make sure I have it all back together properly. 
In this series I am refurbishing my W124 instrument cluster. In the last part, I removed the cluster and lubricated the speedo cable. For this part, I am repairing the W124 outside temperature display. The main problem with these displays is that when exposed to too much hot sun, the LCD panel ‘bleeds’. Over time, this makes it increasingly illegible, not to be mention ugly. I previously fixed the displays in both my old 300SE and the 560SEC. The W124 outside temperature display is basically the same as the unit found in the W126 and W124. They are just in different housings. 
The good news is that replacement LCD panels are available. The LCDs used changed in about 1988, so for the 300TE I needed to use the newer version of the LCD panel. I also bought another earlier one to fix a spare W126 unit I have on hand. The W124 outside temperature display unit just screws into the back of the instrument cluster. Its the first thing you have to remove to get the gauges out, so now was a good time to repair it. To repair the W124 unit, there are four small screws that must be removed. On this model, the upper and lower parts of the housing must come apart to get to the front part where the LCD panel is. 
The later unit as on my 300TE has a more sophisticated baffle for the bulb that illuminates the display. Otherwise there are basically the same, with the two black ‘blocks’ that transmit the signal from the PCB to the LCD panel. The dot at the top of the LCD panel faces upwards. 
As I purchased two LCD panels, a new one and an old one, I had the issue of not being able to work out which was which. Probably it would be evident with a strong magnifying glass, but I couldn’t tell. I tried one, and as it turned out, it was the wrong one. The W124 outside temperature display is a separate unit to the instrument cluster, so its possible to test it without installing the entire instrument cluster. 
It also looks like the blub in my unit has blown. It would be easy to change if you are good at soldering. This is soldered onto the PCB, and I’m terrible at soldering. For now, I’m going to leave it as is. I’m still pretty happy with this repair. | |
