LED headlight bulb, customized--replacing

In my car, a 1994 Mercedes, the left headlight went out. The part number on the headlight unit–which is a small LED item that is twisted into the back of the fixed headlight position after the fashion of conventional taillights–is H4 9003 HB2; it has two wires, one with black insulation and one with red. Both are connected to wiring from the harness by lengthwise rubberized connectors in a shape similar to the bolt affair on a rifle! I am having no luck finding replacements, even on eBay or Amazon. Any suggestions?

None of these work?

Bolt affair of a rifle? Sounds like they might have been customized maybe?

Doh! didn’t read the title fully. I’d look into replacing the plug on the car to match the standards available.

I seriously doubt that a car that old had LED lamps as original equipment. Unless the complete lamp assemblies have been replaced, lenses, housings etc. You should install the incandescent bulbs that the manual calls for.


The stock lights in a 1994 Mercedes used halogen bulbs called H4. Two variants of this bulb exist and are called 9003 and HB2. So that isn’t a part number in the OP but just the style of bulb.

There are conversion kits like this one that allow LED versions of these bulbs to replace the halogen ones. Presumably the OP’s car has one of these kits installed.

But I don’t understand the difficulty in finding replacements. A quick search for “H4 9003 HB2 LED replacement bulbs” yields a bunch of places they can be purchased.

I suspect OP’s referring to the locking lugs on the sides of the lamp socket that rotate in the reflector housing to lock the socket in place. (They’re usually rectangular lugs, reminiscent of a rotating bolt’s locking lugs.)

In other words, a non-standard description of a dog-standard feature of non-sealed-beam headlamp socket.

We’d need a picture to know for sure, but, maybe HID?

What he is describing sounds like this guy (notice the red/black wires):

It isn’t clear what the OP meant by the connectors resembling the “bolt affair on a rifle” but red and black wires are a pretty consistent feature of most electrical assemblies.

Since the only thing that really is clear about the OP is that they are LED bulbs, it stands to reason that they probably aren’t HID bulbs.

The kit to convert the original halogen lights to LED lights includes cables that go between the new bulbs and the car’s wiring harness. The connector at the end of that cable should be standard and compatible with any LED version of the H4/9003/HB2 bulb.

Again it isn’t clear from the OP but I suspect all he needs to do is buy another bulb of the right type and it will fit the connector the old bulb was connected to. The wiring in the car isn’t important for us to know about unless he’s looking to replace the entire conversion kit.

I finally found a compatible unit, after a little asking around. I went to a car audio shop, which had the unit I needed; they fitted it in the headlight frame and it works fine. :slight_smile: