Depo Euro Headlamp Fix - PeachParts Mercedes-Benz Forum

BillGrissom · #1 03-01-2020, 04:45 PM

A year ago, I bought a pair of Depo Euro Headlamps for my 1984 300D. My son complained that the left lamp was weak and yellowish. I swapped in a new halogen H4 bulb, but no difference. I found the voltage difference at the bulb was ~6 V, with most of the drop on the ground return side. The problem turned out to be on the backside of Depo's 6-pin connector. I found they had just crimped the pins against a ring terminal on each wire, then covered with apparently a glue-gun to secure the cables. I first tried soldering the rings to the pins, after picking off the glue. An ohmmeter measured OK, but later the problem returned. It appeared the solder didn't wet the pins, so they might be aluminum, as shown in the photo (after soldering).

I knew the same male 6-pin connector is used for the aft lamps in the trunk. Luckily I had a spare lamp bar so took the connector from that and made a steel bracket to secure it, as shown, using the lamp-bar channel metal. If you haven't played with M-B connectors, they are kind of nice since they have big pins which are easy to re-work. The wires slide thru a cross-hole and are soldered in place, so easy to re-use the pins. Of course, if changing both sides of the wiring, you could use any connector like the Metri-pak used in most cars since the 1990's. I get full 12 V at the 3-pin headlamp connector now and the left is as bright as the right lamp. As I recall, the right headlamp was different and had 57 "spade" terminals on the other side of the round pins. Indeed, I had trouble with those slipping off from the outset so soldered them together (brass-tin on both sides, so easy). Depo needs to hire smarter designers.

Before storing the OE connector away, I played with it a bit. I found I could insert a 12 awg stranded wire in the pin cavity, which was fairly tight, then solder and it felt secure. But, the solder still didn't appear to stick to the pin surface, so might not be robust. If those pins are aluminum, perhaps a better attachment would be to use a self-tapping sheet-metal screw, which fits the inner hole, to clamp the ring terminal tight against the pin. I would also use silicone grease so no future corrosion. That would have been easier than my repair, plus not have to scrounge a male connector.

vwnate1 · #2 03-01-2020, 06:31 PM

I bought a set too, they were so cheap and nasty (! no adjustment !) I eventually took them out and replaced with original ones before Mercedes discontinued them .

I like the soldering fix ~ I too solder a lot of things so I never have to worry about them again .

Diseasel300 · #3 03-02-2020, 09:23 AM

For soldering dissimilar metals, you might try using some activated rosin flux on the joint before you flow solder. Unless it's a really contaminated joint the activated rosin flux will generally let the solder stick, at least to some degree. Clean well with alcohol afterwards, leaving the flux on can corrode copper wire.

Mike D · #4 03-02-2020, 09:36 AM

Good fix!

vwnate1 · #5 03-02-2020, 09:40 AM

Quote:

Originally Posted by Diseasel300

For soldering dissimilar metals, you might try using some activated rosin flux on the joint before you flow solder. Unless it's a really contaminated joint the activated rosin flux will generally let the solder stick, at least to some degree. Clean well with alcohol afterwards, leaving the flux on can corrode copper wire.

Thanx ! .

One of to - day's projects is to up grade the brake lights in my '82 240D ~ I want to add two bulb sockets using the unused spaces in the original taillights ~ I'll use correct factory black wire with a red tracer and some original bulb holders salvaged from a junked W113 and fit some # 1156 LED bulbs for better safety .

BillGrissom · #6 03-08-2020, 06:05 PM

Quote:

Originally Posted by vwnate1

Thanx ! .

One of to - day's projects is to up grade the brake lights in my '82 240D ~ I want to add two bulb sockets using the unused spaces in the original taillights ~ I'll use correct factory black wire with a red tracer and some original bulb holders salvaged from a junked W113 and fit some # 1156 LED bulbs for better safety .

Good plan. In a few locations, I swapped to LED bulbs many years ago. Not quite as bright as incandescent but should last longer so having some assured light is best. I recall a few LED bulbs would fit in some 300D locations since couldn't fit thru the hole, even thought the correct bulb#. I have seen numerous newish cars on the freeways lately w/ no tail lights while the headlights are working. Seems to be a reliability issue.

vwnate1 · #7 03-08-2020, 08:47 PM

They're in and working dandy .

There are myrad different configurations of automotive LEDs, my brother favors they bigger ones shaped like paddles but as you said, they won't fit the holes in the lamp's reflectors .

Careful application of # 1156 LEDs will speed up your turn signals significantly .

Daily I seem to see ever more poor drivers .

ColLonewolf · #8 03-10-2020, 05:58 PM

What are we using for bulbs in these euro lights? Especially need the fog light bulb. Thanks.

vwnate1 · #9 03-10-2020, 06:41 PM

Depo lamps come with Chinese bulbs that work great but like most things from China have a very short service life .

Then just buy Hella bulbs, be wary of super high output bulbs as the factory wiring , switch and so on isn't up to the extra current load .

Whenever you up grade headlamp bulbs you're supposed to add relays, most cheat and then complain when the wiring melts after a while .

ColLonewolf · #10 03-10-2020, 10:05 PM

Bulb part numbers? Is there a diagram of recommended wiring update with relays?

vwnate1 · #11 03-10-2020, 10:30 PM

here's a bunch of info on the relays and wiring needs, remember : the current carrying wires need to be good quality 10 gauge or 1.5 MM fine stranded wire .

https://www.google.com/search?source=hp&ei=6UxoXsiZA-Cs0PEP7Mqa8Ak&q=headlight+relay+kit&oq=headlight+rel&gs_l=psy-ab.1.1.0l10.1737.12092..19618...0.0..0.207.1214.11j1j1......0....1..gws-wiz.......0i131.CbXpdopDtzk

vwnate1 · #12 03-10-2020, 10:38 PM

O.K., here's the basic plug and play lamp assembly, I'm still trying to find the dang replacement bulbs.....

https://www.pelicanparts.com/More_Info/PELH470477.htm?pn=PEL-H4-70477&SVSVSI=3304&DID=55715

vwnate1 · #13 03-10-2020, 10:44 PM

This is the one I use, you can clearly see the typ of replacement bulb, still searching....

https://www.pelicanparts.com/More_Info/70476.htm?pn=70476-M44&SVSVSI=3304&DID=3874

Cheaper too but not the Euro style you're looking for .

vwnate1 · #14 03-10-2020, 10:46 PM

here are the fog/driving lamp bulbs .

I bought a pair of the yellow ones, they work great but being Chinese made how long will they last ? .

https://www.pelicanparts.com/catalog/SuperCat/3304/MBZ_3304_ELLITE_pg5.htm