The first car in line is my 1977 Mercedes-Benz 450SLC.    When I purchased the car in 2003, it had a 90’s era cassette player installed.   I had just returned from America and had the Pioneer MP3 CD player from my 1986 300E available, so I had it installed in its place.   For a radio that is over 20 years old, the Pioneer has done well.   In the last year or so, it has started to play up a bit.  It also lacks hands free function, an important feature with the strict mobile phone use laws in NSW.     One option would be to replace it with a modern head unit that has this capability, like the one in my 560SEC.     The modern radios especially look out of place in this car, so now was the time to replace it with a proper Becker radio.

My 450SLC would have been sold new with a Becker Mexico Cassette.    I actually found the original amplifier behind the dash, not hooked up.    There are more varieties than you might think of this this Becker radio.   I looked at a lot of cars for sale, and consulted with a MBCNSW member who has a very original 1977 450SE.

Through this, I was able to try and piece together some of the differences.   I’m still looking for more information on this topic to really understand, but the visual differences seemed to be as follows:

• The very early radios have a small balance wheel under the volume knob.  I understand these radios were available around 1971-1972.    The AM/FM buttons are labelled M and U.   The model insignia says Becker Mexico Cassette at the top, with Mexico in script, and the Becker and Cassette being lower case.    There is no stereo light on the radio, but the tape flap says stereo.   There are no markings for the secondary functions for the knobs.    The rewind/fast forward buttons have a single arrow pointing inwards.  I do not believe this radio was supplied on Australian delivered cars, but is seen on imports.   I’m also told there is a slightly later version of this radio with the stereo light, but not the other changes of the mid production model.

• The mid production radios do not have the balance wheel.   There seems to be versions that have AM/FM on the buttons and some say M/U.   The model insignia still says Becker Mexico Cassette, but the Becker and Cassette are now in upper case.    Secondary functions are shown for the two knobs, left being bass/treble and the right being tuning sensitivity.   RW and FF buttons are double arrow facing outwards.    I still haven’t worked out if there are distinct varieties here.   I’ve seen both AM/FM and M/U buttons in the same (M) serial number range, so the variations may have been based on market too.

• The late production radios are similar to the mid production units, except the model insignia says Becker Mexico in all caps, with the cassette door now saying Cassette.    I’ve only seen this model with AM/FM buttons.   From what I have seen this was available from 1978 onward.    For Australia, that means 1978 only, as for 1979 we got the black Becker with the big knobs.

My 450SLC is a 1977, so it should have the mid production version.    I would have been happy with any of them, as the difference is quite small, but I have been able to find an early and a mid production, both of which need repairing.  Hopefully at least one of them is repairable.    I don’t own any cassettes, so I am just going to get the radio working.

It is possible to have these radios modified so the cassette function is replaced with a Bluetooth module.   I may do that, but I prefer to keep things original so I have come up with a different solution.   I’ve found an FM injector that not only allows mobile phone music playing, but also hands free.   In the past, I was not a fan of playing the music through a phone, as I had a work phone that was managed by my employer.   Therefore, I couldn’t load my music on the phone.   My current employer does not have this arrangement which gives a bit more flexibility.

I also plan to use this FM injector on my 560SEL, as I have not been that happy with the normal FM transmitter I have in that car.   I get a lot of interference, and I still need to drive around with the ashtray hanging open.

While my primary focus has been finding a solution for my 450SLC, I was also interested in doing the same for my 560SEC.   It has an Alpine MP3 CD player I quite like.    But it doesn’t look as good in the car as a Becker does.   On checking the data card, the car came with a Grand Prix Cassette (option code 251).  Unlike in Australia, the CD player was not standard on 560 models in the UK.   My goal was to source the right radio, even if I didn’t install it right away.   These radios are getting more and more desirable, and harder to find.   Better to get one now, and have repairs done while parts are still available.

The original Becker radio would have almost certainly been a model 754 or minor variation.   This was available in 1986 and 1987.    The 754 is not the best radio to re-install because it uses an internal lithium battery to keep the radio unlocked.  If this battery gets too old, the radio locks and it must be unlocked by a Becker service centre.    A much better option is a 1402 or 1480.   The 1402 was standard in Australia for the 126 (outside the 560) from 1988 to at least 1990, and has a code to unlock.    This means no battery to mess with.    The 1480 was used in the USA for 1990 and also simply requires a code to unlock.   It has a very similar face, but with a silver strip running along the front, and the Mercedes-Benz logo on the tape door.

It’s probably better to avoid the 780 and 1432.    The 780 integrates with the factory alarm, and was fitted to cars sold with the alarm system.    If not removed with the alarm properly disarmed, the radio is locked and again requires a Becker service centre to unlock.    It looks like it can be installed without the alarm system connected, but its one more risk of an issue.   The 1432 was a two piece unit, with the second piece in the boot, same as the CD player.   Most of the time you see them for sale its just the head unit, which is useless without the other piece.

I was able to find a 1402, which was working when removed from the sellers car.   It was missing the plugs, which I got from USA eBay.    I was also later able to get some more from the Las Vegas junkyard.    Since I am going to send the Mexico cassette off for repair, I wanted to test the 1402 as well.

In order to make a test kit, I grabbed the original speakers from the 420SEL parts car.   The Becker was long gone, but the speakers were still original, and even better had their original connectors.   Making it even easier, there is a connector very close to the speaker, so I had them out in minutes and they plug directly into the 1402.   I then used an old car battery I have lying around for testing, and some test wires to make a temporary harness.

In short order I was able to get the Becker 1402 to fire right up.   The wire for illumination worked correctly too.    It was even able to pick up a station playing country music without an antenna.   I’m not a fan of country music, but I was very pleased to hear it coming through the speakers.

Next I hooked up the FM injector.   In no time, I had music from my phone playing through the Becker radio.   Despite the original speakers from the 420SEL, it sounded ok, if a little tinny.    Will sound much better with good speakers.     It’s also been good to validate the FM transmitter.   I’ll likely be installing it in my 560SEL too.    It’s called an iSimple Tranzit BLU HF.   Not sure if its a temporary lack of stock, or it’s going out of production, but I grabbed a few while I could.   They were about a third of the retail price, so not a bad deal.

Due to the simplicity, I may even install the FM injector into the SEL before I do the full Becker Radio installs in the other cars.

The post Planning Becker radio installs appeared first on Classic Jalopy.

The radio in the car is an early 2000s unit I originally bought for my 1986 300E when I lived in Denver.   When I sold the 300E I put a cheap radio back in and kept this unit.   It’s a Pioneer Premier which is like Lexus is to Toyota.   It was a pretty good radio for 2001 – with MP3 CD function and more.    I had the radio fitted to the SLC after I purchased it in 2003 – the car had a fairly crappy 90s unit installed at the time of purchase.    Its doing pretty well to still be working after 20 years.   At some point I will probably install a retrosound unit similar to the 250SE, but that is a future project.

The first task was to remove the radio and check to see if it had power or not.   As I didn’t install the radio myself, I did not have the correct DIN removal tool.   I purchased a full set of DIN tools online.   I figured it would be a useful tool for the future.

The purchase was definitely worth it, as I had the radio out in a matter of minutes.    The pioneer tools were a perfect fit – I guess they haven’t changed them in 20 years!   Some of them have rather odd shapes, so but its good to have all the standard types.

The steering wheel is only loosely on at the moment as the odometer is out for repair.  I found it easier to remove the instrument cluster and give the radio a bit of a push from behind.   As with the other stuff I removed, the 450SLC radio wiring is pretty messy.   I didn’t try and clean that up as I’ll do it at the same time I replace the radio and probably install new speakers.

Once the radio was out it was pretty apparent what the problem was.   The yellow wire for permanent 12v was connected to and old bit of speaker wire I had removed.    The switched 12v was working correctly however.    This old bit of speaker wire had been connected to one of the old car phone bits which was in turn connected to the fuse box.

As modern radios use more power than the original Becker units, I figured the best approach was to run a new wire from the battery to the radio, with an inline fuse.   This is pretty easy to do with the under dash panels removed.   There is a big rubber grommet near the battery that lets a bunch of vacuum lines and wires go from the engine bay to the cabin of the car.   I was able to push a new wire through fairly easily.   It was actually easier to do it from the cabin to the engine bay as the vacuum lines turn almost 90 degrees once they enter the cabin.     I then use an inline blade fuse holder and a connector to the positive battery terminal.

A quick test showed the radio working.   The new 450SLC radio wiring is much neater than before and I have a working radio again.

While I was there, I had another issue to investigate.   I had replaced the sunroof switch about 10 years ago, but without the instrument cluster removed, I couldn’t plug it in without removing the rear dome light switch.   This gave me access to plug in the sunroof switch.   At the time I figured a working sunroof was more important than a working dome light.    However, with the dome light switch plugged back in, I blew fuse #1.   In the end I just disconnected the switch again.   I have not really missed the dome light since I disconnected it.

The post 450SLC radio wiring appeared first on Classic Jalopy.

This car still had the factory fader switch installed.   That means that there is only a front and rear channel for the radio.  All the speaker wires go through the fader switch that controls the front/rear fade.    After a while these switches stop working well, and can be bypassed when using a modern radio – if you’re happy to cut the factory wiring.

While it looks complicated, to remove the fader switch, what is needed is to cut the wires that come out from near the fader switch itself – near the switch the smaller set of wires are for the rear speakers, and the larger set go back into the dash for the front speakers and radio connection.    Therefore, so long as the speaker wires are cut before they hit that section of wiring that joins them up, they can simply be wired into the new radio.   A 9v battery is a good way of verifying which speaker is which to ensure the radio is correctly installed.

If the wires are carefully cut, there is enough slack to re-install the radio without having to re-wire the speakers.

The post W123 Radio Upgrade – bypassing the factory fader appeared first on Classic Jalopy.

Overall the car is looking much better.  Despite going through the paint in a few places where it was very bubbly, there is now some shine on the paint and the rear wings especially are not a matte finish anymore.   I will do one more go of the stage 2 polish when I get some time.

I also spent some time trying to work out why my new Radio keeps ‘rebooting’.

The Radio requires two 12v feeds – one that is always on, and an accessory feed.   I had connected both to the point behind the dash were the Citroen manual suggests that radios etc should be wired in, and the accessory feed was going through a spare dash switch so I could turn the radio on and off.

Given that it was an original Citroen switch (I think for Hazard lights) my first try was that perhaps the radio was trying to suck too much power down that wire, so I put in a small relay that was rated 30A.    The radio is still rebooting so my next step will be to wire the 12v directly to the battery.   That will be quite a big job unfortunately!

The post Polishing day appeared first on Classic Jalopy.