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Hella Headlight H4 Conversion
(Ridiculously simple, about 30 minutes ... tops)

One of the very few things that I has disappointed me is the stock sealed-beam lighting on my 1991 e30 325iC. I took a look at the following options:

  • Ellipsoid Conversion: The 1987 to 1989 e30 BMW came with ellipsoid headlights, these are widely accepted to be a big improvement over the sealed beam. They are however difficult to find used in good condition, and expensive to buy new. Also, to install these in a sealed-beam car a certain amount of re-wiring that must be done.
  • Hella H4 Drop-in Conversion: Hella makes a European style 5" light that accepts an H4 bulb, and is a direct replacement for the sealed-beam. The plusses are that it puts out volumes of extremely clean light, is inexpensive at about $40 a light, and is a direct replacement for the sealed-beam. The only downside is that they are not DOT-approved for on road use.

After unsuccessfully looking for a good set of ellipsoids for some time I decided to go with the Hella H4 conversion. Two days and $80 later I had a set of low beams in hand and was ready to convert.

As you can see, the sealed beam puts out a pretty weak amount of very yellow light.
The lights were delivered from Classic Car Garage with new Hella H4 Bulbs, for $36.99 each. They go together simply enough: insert bulb, secure with wire clips, pop the rubber boot over with the bulb tines correctly lined-up and push down until it is secure.
Disassembly is easy - remove the three clips at the blue arrows, and unscrew the two Phillips head screws at the yellow arrows. The light grille should come right off.
Another view of the light grille tabs.
Remove the three Phillips screws securing the bulb retainer ring, be careful they are easy to lose and hard to find!
At this point the bulb should slide right out and you can see the three-prong wiring connector. Slide the connector off and remove the bulb (save it, you'll need to re-install it next time you need to get your car inspected!) This is a good time to clean the socket and the retaining ring.
Lube the tines with some dielectric grease and slide the connector on the new Hella Light. Carefully insert the new Hella Light in the bulb socket - it really only fits one way, with the "H4" upright in the center of the bulb. Replace the retaining ring (it also only fits one way, with the imprint at the top). Replace the grille and insert the clips, then the screws.
Congrats - You've just drastically improved your lighting!

As you can see, the left Hella H4 bulb is far "brighter" than the old sealed-beam on the right.

Ahhh, clean, clear and voluminous lighting!

Now aim your headlights according to this write-up.

Here is another tech piece I found, if you are the author please give me a shout!

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