With respect to similar issues on the 124, there has been a bit of recent activity on FB groups about the bulb warning light being illuminated even though all bulbs are functional. This was the very first issue I dealt with when I bought my 124 way back 14 years ago. There were multiple cracked joints in the bulb monitoring unit 126 542 03 32, which I resoldered. Problem solved.
theres early and late versions of that package i noticed. Late ones dont have the high currents passing through solder joints at all and are all riveted connections, only the current measurement connecctions (small diameter pins) are soldered to the board and are much much much more reliable. I have these later types. MB occasionally (or at least their suppliers) learn from their dumb mistakes.
@@MMWA-DAVE Yep, I was aware that there were different ones. My 1990 .051 came with 126 542 03 32 (Hella) but I notice that there is also 126 542 00 32. Maybe this is the one you are referring to.
Excellent video. My '97 R129 has the old style robust headlight switch which in itself can be problematic so I replaced it in the hopes of resolving a flashing daylight running lights issue. To no avail. I guess digging into the headlight control module and examining soldering joints there and even the fuse box might be inorder. Electrical problems like these are all so tiresome. Early happy new year btw since you're some +19 hours ahead of my time zone.
Yesterday I've removed the OVP relay and the ECU of my '90 260E; the idle was kinda weird and the acceleration was not soft too. Cleaned and resoldered the contacts of the OVP, even the crimped areas of the connection pins! As there were an empty slot for another possible relay inside without pads and tracks, I've placed a paralel relay with the original to double it's current capacity. In the ECU, replaced those electrolytic caps and a big tantalum one (100uF), this was giving measurement on the tester only whith reverse polarity; I've never seen this before... cracked solder joints are a common issue in older cars; I've been wondering how many switches like yours were disposed in trash instead of being repaired... Happy new year and thanks for sharing!
more people need to be prepared to open things and fix them themselves. Knowledge of electronics and soldering should be part and parcel of old MB ownership
@@MMWA-DAVE I agree with you! As a technician since 1990, I always liked tôe make small repairs in my friends cars, most of them carburated but really electrical issues happen in old cars, some really easy to solve, other not so 👍🏻
