W126 SEC auxiliary fan replacement

Once I got the air conditioning working on the 560SEC it was apparent the auxiliary fan was not working.   As can be seen in the wiring diagram below, the W126 SEC auxiliary fan can be triggered either by high coolant temperature or by refrigerant pressure.   The diagram is for 1986-1990.   In 1990, the W126 went to a dual fan setup.    The fan can operate at two speeds based on a resistor.

My fan would not work even when fed 12v directly.   I struggled to find a replacement fan from a brand I trust.   I wasn’t that keen on a used fan as they are all now quite old and in the hot Australian climate run quite a lot.   In the end all I could find for a reasonable price was Meyle fan.   Meyle is a brand I normally try to avoid as I have found the parts are not a great fit.

The W126 SEC auxiliary fan is not as easy to remove as on a four door car as there is less room to maneuver the fan.   The fan itself is held on by three 8mm bolts.   Two of them can be seen in the picture below.    They are at 2, 6 and 10 o’clock on the fan.   The fan is not bolted on directly, in all three cases there is a mounting bracket.   For the 6 o’clock mount, it is easier to remove the mounting bracket with the fan.   This is a 10mm bolt that is obscured by the bumper.

W126 SEC auxiliary fan

Once the fan is loose, it is a bit of a chore to actually remove it.   I found the easiest way was to move the strut out of the way that mounts the horns and loosen the panels that go under the headlights.   The strut has two bolts holding it on and there are three to remove to loosen the panel.   It was quite dirty underneath the old fan so I gave it a quick clean out with compressed air.

W126 SEC auxiliary fanOnce I had removed the old fan I was able to compare it to the new Meyle fan.   The central ‘hub’ unit on the Meyle fan is a little smaller which makes removal a bit easier.   The Meyle fan also has a balancing attachment which the factory fan did not need.  Both fans do not space the blades evenly around the hub.   The factory fan also had some little felt pads to protect the condenser.

The original fan has a finger guard, which is removable and I had planned to re use it.  As usual the I had fitment issues with Meyle parts – I could only ever get two of the mounting points for the guard to line up at any given time.   When not mounted properly there is too much risk of the fan fouling on the guard so in the end I had to fit the fan without.

Meyle vs factory fanInstallation is generally the reverse of removal.   I found it easier to start with the 2 o’clock mount loosely, then the 6 o’clock mount.   I loosely re-installed the horn strut before loosely fitting that mount before finally tightening it all up and replacing the bolts on the under light panel.    it is quite easy to push the electrical cable through to where it plugs near the receiver drier.

W126 sec auxiliary fan

It’s a shame I could not fit the finger guard.   It would be hardly noticeable I have an aftermarket fan if that was the case.    The next step was to test the fan.  I went for a 20 minute drive in very heavy traffic with the A/C on full.   I brought the car back and left it to idle for a few minutes.   Sure enough, the fan kicked on and slowly lowered the temperature.   Before I replaced the fan it got so hot I would have needed to either drive or shut off the car.

W126 SEC auxiliary fan

I was expecting to need to do more electrical troubleshooting once the new fan was fitted.  I was pleasantly surprised to see it whir into life after the car got nice and hot.   My next step will be replace some of the climate control vacuum elements which are preventing my centre vent from working.     I’ve kept the original one to see if it can be repaired.   The auxiliary fan in my 300SE occasionally pops the fuse so it will probably need replacement at some point

Citroen DS Instrument cluster repair

Earlier in the week I had identified the lack of instrument cluster lighting was due to a crack in the instrument cluster circuit board.  The crack was causing an intermittent broken circuit.   I wasn’t able to find much on the internet about Citroen DS Instrument cluster repair.  Looking at the board it looked like a very simple design.  That gave me the confidence to come up with my own solution.

The easiest course of action would have been to solder a wire in place.   I didn’t go with that approach as there is no soldering used on this circuit board at all.  It uses rivet looking connectors to take the power to the other side.    I wasn’t sure how well the backing would hold up to the heat and was worried about the solder breaking off.  The board flexes each time the power connectors are removed or installed and it can get hot in behind the dash.

The copper tracks on the board are particularly wide.   This gave me enough room to drill small holes in strategic spots.  I chose spots that were wide enough so I did not touch any other tracks.   I then used conductive screws to bring the power to the back of the board where I could use wires to get past the crack.    The bolts are 3mm.

Citroen DS instrument cluster repair

The four screws are set up so I can bypass the break.  The break is near the square hole in the top left of the picture.   The outer track is for ground and the inner for +12v.   The screws stick up a bit more than the rivets do, but they are quite secure and are not going to come off over time.    You don’t want normal screws at the hardware store as most of them are coated and have low conductivity.

The picture above also shows my quite rare temperature gauge.  This was generally fitted to cars in very cold climates only.  It is very useful in hot ones too!

Citroen DS instrument cluster repair

Once the screws were in place I was able to create two lengths of wire and crimp eyelet connectors on each. This is a similar approach to the tachometer.  The tachometer uses the rivets instead of the screws though.    It was then a simple matter of connecting up the wires around the back of the speedometer.  The wires are tucked so they should not be in the way.   The only downside is the board sits up a bit  more on this corner.  The bulb just near the wires leaks a little light because it is sitting up.

Once I put the cluster back in I was rewarded with lights that worked without flickering or pushing on the cluster.

Citroen DS instrument cluster repair

While I was at it, I also swapped over the petrol gauge from the parts cluster.  It was in much better shape than the one on the car.    I have not yet taken the car for a test drive, as the weather in Sydney has been poor.  I expect my home Citroen DS instrument cluster repair to hold up well.

Citroen DS Instrument Cluster Lighting

Recently during a night drive I discovered my Citroen DS instrument cluster lighting had failed.    In Sydney, where I live, this is a huge problem as the city is bristling with speed cameras.     So many that I could lose my entire licence in about 10 minutes driving near my house doing only 10 km/h over the speed limit.     I regularly drive at night, so I needed to find a solution.

My first assumption was the rheostat had failed.   The rheostat is the dimmer that lets the driver control the brightness of the instrument cluster lights.   Over time, these can develop dirty connections.    On the DS, the rheostat is actually not part of the cluster, but under the steering wheel.   This made it easy to test.   Once I had removed the instrument cluster I could use a multi-meter to check that I was getting 12v to the pin for instrument lighting.    I was.

Next step was to check the cluster itself.   It is simple to remove on the DS – four screws, three electrical connectors and the speedo cable.   Another four screws opens up the cluster.

Citroen DS instrument cluster lighting

At first glance, there did not appear to be anything wrong with it.   I didn’t think it would be a blown bulb because there are two of them and both were working before it failed.   In any case both bulbs looked good.

Readers who are familiar with the DS will immediately spot that my instrument cluster is not correct for a 1970 model car.     It is either a 1973 model or has been pieced together from multiple models years.    How do I know?   For 1970 and 1971 the instrument clusters had long needles for the speedometer and tachometer, and the braking distance was a ring set above the speedometer needle.    Specific to 1970 models was markings on the speedometer for the shift points.    In 1973 the clusters went to long needles and some time in 1973 the indicator lights flash together on the dash rather than separately.

When I purchased the car it had this cluster with a different MPH speedometer with a short needle.   Later, I changed the speedometer for a KM/H unit and the front cover for a nicer one.   I don’t know if the entire cluster or just the speedometer was changed in the past.   I keep an eye out for the right 1970 cluster with shift points for a DS21 but so far I have only ever seen the D Special/D Super unit.

After doing more testing I found that the cluster could light up, but it was extremely sensitive.   It would stay lit up if the cluster was dismantled and not in the dash properly, but if i bumped it or re-assembled it the lights would no longer work.

Citroen DS instrument cluster lighting

I also noticed that one of the bulb holders was cracked so I changed that one.   That change seemed to make it a bit less sensitive, but now knowing the root cause I’m not sure that was actually the case.  I would get it back in the car and it would work until pushed back into the dash properly.

Citroen DS instrument cluster lighting

At this point I was really stumped.   I got out my spare parts instrument cluster and dismantled it to see if I could spot any differences.     Perhaps there was a bad connection in the cluster somewhere?  I removed the circut board on the parts cluster which is the simplest circuit board I have ever seen.   There are almost no electrical components, just copper channels to direct power to the various bulbs.    The board is so simple I couldn’t see how a bad connection would even occur.

I went back to the good instrument cluster and removed the circuit board to compare.   This immediately showed up the problem.   There is a crack in the board!  The place it is cracked has two functions only – power and ground for the cluster lights.   The crack was not noticeable until the board was removed which was why it was so intermittent and why the cluster was not working pushed back in the dash with more pressure against it.

Citroen DS instrument cluster lighting

Now I know the problem it should be a fairly simple repair.   The board is so simple even that thick section has only two tracks.     I’m not sure if the crack has been there a while and it just got worse removing the cluster for the fan light, or if it somehow cracked during that modification.

2020 Shannons Sydney Summer auction

I went to preview the 2020 Shannons Sydney Summer Auction today.   If you had a budget of about $20-$35,000 AUD, there are a lot of interesting cars to choose from.    Shannons do a pretty good job of finding a good variety of cars for each of their auctions – both in price range and types of car.    They are a bit more picky than other firms such as Lloyds or Grays Online.

This auction also had a large number of the numeric numbers plates at massive prices.   I’ve never seen the appeal of these.

Any fans of big German coupes, with a budget of $15-$20,000 will have three good choices at the auction.   Lot 33, a 1983 Mercedes-Benz 280CE looked like a really nice example.   I’ve seen 280CE’s that were far worse being advertised (but not selling) for significantly more.   The 280CE is an underrated car and doesn’t command much of a premium on the sedan for some strange reason.   I doubt that will last.

2020 Shannons Sydney Summer Auction

Next is Lot 34, A 1973 Mercedes-Benz 350SLC.    This SLC is finished in a lovely period colour, with some of the nice early touches like a small mirror on the drivers side only and front radio antenna.   The wheels are particularly ugly, but a set of original wheels or even Pentas would have the car looking a lot better for a reasonable outlay.    I would also remove the aftermarket chrome wheel arches.    I did on my 450SLC.

2020 Shannons Sydney Summer Auction

Finally for the more sporting driver is Lot 35 – a 1986 BMW 635CSi.   This car is equipped with the preferable manual transmission and provides a good alternative to the Mercedes-Benz models.    This E24 6 Series is one of the best looking models they ever made.

2020 Shannons Sydney Summer Auction

Another car that stood out to me is Lot 53 – The 1926 Frazer-Nash.   This was one of the more expensive cars on display with a range of $130-$150,000.   It has the chain drive that these early Frazer-Nash cars are well known for.

I also admired Lot 59, The 1941 Packard 120.   While the 120 is a ‘Junior’ Packard, it is still superior to most other cars from that time with its straight eight motor, high build quality and period interior.   This car has not been over-restored like many and things like a leather interior added.    Many Packards have big limo bodies on them befitting their high purchase price, but this 120 has a smaller coupe body that would be much nicer to drive.

Packard 120

At the Auction was a Maserati Kyalami (lot 69), which looks like the one I had stored in my garage a couple of years ago.   As there were so few right hand drive cars, I suspect it is.   The Maserati sounded amazing as it drove in to storage.

Finally some interesting cars included a Jaguar MKII 2.4 with great patina and a reasonable $15-$20,000 range; A Rolls Royce Silver Spirit III, imported from Japan, a beautifully restored Riley RMB and a 1936 Jaguar SS project car.    I think of all of the cars at the 2020 Shannons Sydney Summer auction , I would have the Packard.

Auto Brunch St. Ives February 2020

I attended the monthly Auto Brunch event in St. Ives Showground today.    This time I took my DS.   It was pretty dusty from all the smoke in Sydney, but still got a lot of attention.     Even though I have been four times,  there can still be a lot of variety and different cars I have not seen before.   This month there was a whole line up of Jensen Interceptors.   I’m a fan of the interceptor – it’s a big brute of a car combining Italian Styling, British engineering and an American (Chrysler) powertrain.

The Mercedes Club also featured Auto Brunch as an event for the first time so there were far more Mercedes-Benz on display than there had been in the past.   This included a fair number of 107 SLs and SLCs as well as a nice 280SL Pagoda, 190SL and W108 3.5.       As well as the Mercedes-Benz display there were also a fair number of Alfa-Romeos.

As usual, there were good line ups of Porsches, MGBs and E-Types.      Its kind of funny that the cars that are considered rare and valuable are more common than the pedestrian models.   When was the last time you saw a 2.8 XJ6 for example?  Collectors pay for production rarity, not actual rarity.

The row I parked my DS featured a 2.5 liter three cylinder motorcycle.   It had the largest engine in the row – larger than an MGB, my DS, a landcruiser, a couple of volvos and more.

One of the good things about the Auto Brunch event is that the venue is large so there is never a chance that you won’t be able to find somewhere to park.

Side by Side Parker one year ownership report

It is almost a year since I installed the Hero Hoists side by side parker.   overall, I have been very happy with this hoist.     It has freed up some space to work in my garage, without having to sacrifice some of the rent paying cars I store in there.  I’ve had no problems with it.

Hoist

It is a tight fit in my garage, but I knew that going in.   Being able to use the full width and height of the hoist would make it even better.   Even with my limitations it is still worth it.

Due to my ceiling height, the E-type and 450SLC always sit on the top.   I can modify the ceiling past the last beam to get about another 5-8cm of clearance which I will do at some point.  That will allow the SEC to go up top as well.  Generally the 560SEC and DS park below.  The DS must be put on its lowest suspension setting to park underneath.   I try not to park the 250SE underneath as I don’t want a chance of an oil drip on the soft top.

What I like about the hoist:
  • It is easy to use and doesn’t require air lines to release the locks.
  • It seems sturdy and well made.
  • I was able to put it together myself, although it was not an easy task.
  • I was able to slightly modify it for my setup.
What I am not as keen on:
  • The ramps are really heavy.   To the point I have split two set of pants moving them!
  • I find the rods for the locking mechanism a bit flimsy and in the way.
  • The aluminium inserts were very expensive, so I had a lot of drips until I made my own wood inserts.

The main downside of the hoist is that it can be a bit of a production to get down the top cars.  By the time three other cars are moved and the hoist lowered, a car extracted then the first three cars put back in the garage, it takes 30-40 minutes.     The double hoist means both lower cars must be moved.    I didn’t have the width for two hoists, and it would have cost 50% more.   Plus, the extra posts would have been in the way.

At some point I may look at some lighter ramps to use as an alternative.

M103 Distributor cap and rotor

Today I changed the Distributor cap and rotor in my 1986 300SE.  I bought the new cap and rotor about two years ago but only just got around to changing it.   Unlike on the earlier engines, the M103 distributor cap is a fiddly job.   Instead of sticking upwards, it comes out sideways as it attaches to the camshaft.

I find that whenever I buy one of these older cars, chances are the distributor cap needs changing.   It is not generally an expensive part on the mainstream engines, and can make a big difference to the smooth and reliable running of the engine.  An old and pitted cap is going to produce a weak, inconsistent spark.    I normally just purchase a cap and rotor when I buy the car.  On the off chance it doesn’t need replacing it is good to have a spare.

My 86 300SE is no exception.   The cap wasn’t in terrible shape but it was clearly worn and ready for replacement.  The contacts were worn and so was the rotor.

M103 distributor cap

The M103 distributor cap differs from the other cars because of how it connects to the camshaft.  To remove the cap, there is a cover for the plug wires that snaps off.   Next, three 5mm allen bolts hold the cap to the engine.   Two of them are easy to see but the third one is underneath the cap and only just visible from the left hand side.   I found it easiest to remove it with an allen socket and a small extension.   Using a 1/4″ ratchet made it easier to clear the Serpentine belt.   I used an adapter for my 3/8″ socket into the smaller ratchet for this purpose.

It is easier to remove the plug wires first.  I found there wasn’t clearance to remove the cap until the plug wires were removed anyway – the fan gets in the way.    The actual distributor cap has a black cover that provides the mounting points for the plastic cover and splash protection for the ignition wires.   On the surface, mine looked ok but on closer inspection I would have preferred to change it.   It has a couple of small cracks in it.    In the picture above, the old M103 distributor cap on the right still has the cover attached.

Once the cap is removed, the rotor requires 3x3mm allen bolts to remove it.   In my case, one of the bolts was rounded off.   It was quick easy to remove with vice grips, at the expense of breaking the old rotor.

M103 distributor cap

I gave the inner plate as good a clean as I could.   Ideally I would have replaced this too.  As can be seen in the picture above it has seen better days.

In total, the job took about an hour to do, including the rounded off bolt.   I had not changed an M103 distributor cap before, so it would likely be faster next time.      Note, that the M104 engine is very similar.   The M104 is basically a DOHC version of the M103.  More power, but also even more prone to eating head gaskets.

Youtube tips – shifter bushing and rounded bolts

Today I did an engine and transmission oil change on the 300SE.   I don’t normally post basic maintenance to this website as it really isn’t that interesting.   In this case, I used to tips I learned form MercedesSource videos that really sped up the job.    MercedesSource are an online parts vendor, who also make some useful special tools.   The owner, Kent, runs a youtube channel to promote the business.  I’ve bought a couple of his special tools over the years and found them quite useful.

300SE

The first tip was for removing the bolt from the transmission oil pan.   This bolt uses a hex fitting, which had been rounded off by a previous workshop.   Last time I changed the transmission oil I made a huge mess as I had to remove the pan without first draining the oil.   I obviously didn’t want to damage the bolt without a new one on hand.

This time I had the new bolt ready to go.  The tip is to use a chisel to tap a divot into one side of the bolt and then tap against that divot in the direction to unscrew the bolt.   This technique took all of a few seconds to remove the bolt.   The new bolt was quite cheap.  I don’t remember exactly how much as I purchased it a couple of years ago.

While bolting the transmission oil pan back on, I noticed that my lower shifter bushing was bad.   It had largely disintegrated and the shift rod was no longer snug in the transmission gear selector.   The 70s and 80s cars use a much better design than the 60s models in that there is a clip at the end of the rod that ensures it can’t fall out entirely.  There might be a lot of slop in the lever, but it won’t leave you stranded.     When the bushing failed on my 250SE, I had to use a bulldog clip to make a temporary fix to get the car back into the garage.   Luckily I wasn’t stuck somewhere else.

shifter bushing

I have previously done the shifter bushing on my 450SLC.   There is quite a bit more room to work on the W126.  MercedesSource sell a bushing press that makes installing the new bushings a doddle.  It’s even easier if you use a little rubber grease.     I only needed to do the lower one, the upper one seemed fine.   These are the sort of parts that it makes sense to keep on hand if you own these cars.   They are not expensive and it makes sense to check them each time you look under the car.

shifter bushing

I had also planned to check the distributor cap, but I didn’t get time today.   I’ve not checked it since I owned the car and its a part that is often neglected.   The M103 is a bit of pain to get to compared to other motors.   I also plan to check for vacuum leaks as the vacuum gauge on this car is at the halfway point at idle.   It should be close to the left hand end.   This probably means a vacuum leak.

450SLC Dragging rear brakes – part 3

In part 2, I had been struggling with my new SLC rear Calipers.   As outlined in that section, the new calipers I had on hand are for models not equipped with the anti-squat rear suspension.   This was because USA models were not so equipped.   The hard lines were too short to fit properly and fouled on the suspension bump stops.    I dropped the car off earlier in the week to have new hard lines made up that fit, and to change the flexible hoses.

I have since found out that I made a pretty stupid mistake.   Instead of checking the new parts properly, I used the old ones to determine how they should fit.   In this case, I fitted the calipers based on the position of the old ones.   If I had checked the part numbers properly, I would have seen they were on the wrong sides.   Additionally, if I had used even a modicum of common sense I would have seen the bleeders were facing down, not up.     Why is this a problem?   Having the bleeders facing down means it is pretty much impossible to bleed the brakes.   Instead of pushing the air out, the fluid will just run out leaving air in the calipers.

The brake shop first put the SLC rear calipers on the right sides.   Then they made up new hard lines for the rears to go from the hose to the caliper.     After that, they changed the hoses.   The fronts were not much of a problem.     They had the same problems I did with the rears – no matter what they tried they could not undo the fittings.    I suspect that due to the extreme heat from the sticking rear calipers, the metals were almost welded together.

Stubborn rear hoses - needed for the SLC rear calipers

In summary,  I have an entirely new rear braking system.   New calipers, rotors, hard lines on both sides and hoses.    I also have a new master cylinder and front hoses.    The brakes feel great, and now the brakes are not dragging, the car feels more lively.

Incidentally the shop I took the car to has recently done some work on a 50,000km 450SLC.   They commented that mine rode better and seemed to have more power.   Not bad after 300,000km.

Rover P5 Coupe parts car update

My old Rover P5 Coupe parts car is almost completely dismantled.   It is being parted out to aid in the restoration of three other coupes.   These coupes are in much better condition but needed certain parts to return to the road.    Last I saw the car there were still key parts on it, but all that is left is the engine and transmission.

Rover P5 Coupe

The car is now in a rather sorry state.    It was never in great condition, but it did make the drive back from Canberra to Sydney after the Flynn auction.  Not bad for such a cheap car.    It looks like the bonnet has been used as an outdoor painting bench!

DG Box

The engine is being kept in reserve for the restoration, but the owner will probably sell the DG automatic gearbox as the restoration projects are all manual/overdrive.    It is a shame to see such a rare car parted out, but at the same time this one very rough car is being sacrificed to get three very nice ones back on the road.   This P5 coupe parts car was originally stone grey with a red interior.   When I bought the car it has a poor quality vinyl roof that is unlikely to be factory.