107 blinker flasher unit

Over the last few months, the blinkers have been playing up on my 450SLC.     It started out when the car was first started up, the blinkers would flash very fast.   After a while, I guess the flasher unit warmed up and they went back to their normal rate.    Over time, this took longer and longer to happen, until they stopped flashing at all and just stayed hard on.

It seemed obvious that the flasher unit had stopped working.    I had assumed that the flasher unit was built into the switch, like it is in the later cars.   A friend had a used switch from a 450SLC, so I tried it.   It was clear that this switch was very different to the switch on my car.    On further research, the earlier cars had a separate flasher relay behind the instrument cluster.   It looks like the change happened around early 1978.

This was fairly good news, as while the switches are all NLA, the 107 blinker flasher unit was still available from the MB Classic Centre.   It wasn’t cheap at USD$124 plus shipping, but it was available new.  The part number is 001-544-97-32.

On the 107, the steering wheel is very close to the instrument cluster, so the wheel must be removed to access the instrument cluster.    To get to the relay, the cluster does not actually have to be unplugged, there is just enough clearance to get your arm behind the cluster and replace the relay if you pull it out, but leave it all plugged in.

Once the cluster is partially out, the relay is very obvious, on the right hand side next to the metal supporting brace.   It is that black box pictured below, and just sits in with the normal Mercedes pins.

A quick test before I put the steering wheel back on showed that the new relay was working perfectly.   The new 107 blinker flasher unit fixed the problem.    Taking the steering wheel on/off is the most annoying part of this job, so it makes sense to check first.

You’ll also see that the speaker cover is missing on the drivers side speaker.   I was having problems getting it to hook onto the mount.     It was far easier to do with the steering wheel off.  I was able to use a credit card to get the hooks to line up and then attach the small screws at the bottom.    The final piece of my radio install is now complete as well now.