E30 Lighting Guide + DIY Bi-Xenon Conversion

[Rev Run D]

I have an 89 with the stock US Smilies. One of the high beams is cracked, and the lows are pitted. What options do I have to clean them up?

[hankolerd]

^ Yep, looking at the diagram the fog lights can only be on when the low beams are on, and since the low beams go out when the highs are enabled so do the fogs. The relay guide I linked to also re-maps to allow for independent fogs.

[e30owner]

This morning I switched on the high beams, pulled out fuse #1, and found that both headlights on the left hand side went out. Similarly with fuse #2 for the right hand side. I guess that confirms what you were saying about the hi part of the "lo-beam" bulb being on the hi-beam circuit. Also noted that fog lights go off automatically when high beams go on.

[Das Delfin]

^ do what makes you happy.

[e30owner]

So you're saying the high filament of the "lo-beam" bulb is actually on the high-beam circuit. If that's the case, then I may just stick with stock sealed beams. I'd never be able to sleep at night if I swapped out a 7.5a fuse with 10a...

[Das Delfin]

Just a refresher.. basically the way it works is your low beam is really a dual filament with one lead for the low and another for the high. When you switch the highs on the low filament shuts off and the high filament comes on together with the dedicated high beams. They do this because the high filament is in a different place so the optics are different and orientated higher up. So you have 2 low beams and 4 high beam filaments.

The high beam fuses and wiring control both PAIRS of high beams. So fuse 1 controls the left high beams and 2 does the right pair. If you look at the wiring behind the lights there is simply a jumper wire which takes the high beam signal from the inner light and brings it over to the high beam filament of the outer light. This is why you need to swap the fuses etc etc. Each PAIR will now draw an additional 20w which puts it just over the 7.5a threshold of the stock spec fuses. But as I said before (and as is mentioned in the above link at the very end of the article) the wiring is sufficient for up to twice its operating current. But as an aside, that doesn't mean you should try to run higher wattage bulbs. 60/55w H4s is the best one you can get.

If you want a picture you can see what I'm talking about in the wiring diagram with the two red circles around the headlights and their wiring. It's really not hard to understand. The only weird thing is understanding that the low beam headlight really has two separate filaments inside it, which you can see in that wiring diagram

[Das Delfin]

^ the link above is very informative and well thought out and explains the fuse issue. While yes, generally it is considered a cardinal sin to replace a fuse with a higher amperage just because it's blowing, the case is not so with the H4 conversion. The stock wiring is thick enough to handle a mild increase in current so in this particular case, it is advisable to go ahead and swap out your high beam fuses for 10a

And the H4 high beam output is better than the sealed beam high beam output so I would just swap the fuses and leave it at that. I ran H4s with 10a fuses for over a year before switching to ellips with no issues at all

[hankolerd]

That's exactly what I was wondering about. If "Hi Beam" is 55w from an H1 inner light, plus 60w from an H4 outer light, then the 7.5A fuse on the hi-beam circuit would blow, right?

That is correct. The stock sealed beams have a 50W high beam in the inner light, and the high beam filament in the outer light is 35W, the H1/H4 set-up would be adding a 20W load on the circuit and blow the 7.5A fuse.

The best approach is to follow this guide to adapt your relays, so that your low beam and high beam circuits run stand-alone and the low beams stay on with the high beams. http://users.rcn.com/nifftylion/head...%20-%20Pub.pdf
Or to jump pin's 30 and 30 on the low and high beam relays, so that the low beam relay always gets power, and then remove the jumper wire that was crossing over to the high beam filament (so that it doesn't create a short down the road) - http://www.r3vlimited.com/board/show...ght=high+beams

[AndrewBird]

Maybe I'm misinterpreting this wiring diagram, but aren't there separate 7.5A fuses for each lo-beam bulb and each hi-beam bulb?

Fuse 1 7.5A Left hi beam
Fuse 2 7.5A Right hi beam
Fuse 13 7.5A Left lo beam
Fuse 14 7.5A Left lo beam

Doesn't that mean that each bulb can draw up to about 90 watts?

This is correct, each light has it's own fuse.

DO NOT REPLACE THE FUSES WITH A HIGH WATTAGE.

Fuses are there to protect the wiring, not the lights. If you put larger fuses in you run the risk of melting wiring before the fuse blows. The only reason running a 10A fuse "works" is because normally the load will be under 7.5A. It's when something happens (like a short) that increases the draw that you will have problems.

[e30owner]

it doesn't show that "Hi Beam" is both the single-filament inner light, and the high beam filament of the dual-filament outer light.

That's exactly what I was wondering about. If "Hi Beam" is 55w from an H1 inner light, plus 60w from an H4 outer light, then the 7.5A fuse on the hi-beam circuit would blow, right?

[hankolerd]

Don't think that would work, because I think the power for the low beam relay comes through the high beam relay regardless if high beams are on or off. You can certainly try it though.

I think the portion that your diagram is missing, is that it shows Left/Right Hi Beam on the high beam circuit, but it doesn't show that "Hi Beam" is both the single-filament inner light, and the high beam filament of the dual-filament outer light. The diagram you posted looks more similar to the wiring diagram of an Ellipsoid car, where the low beams were single filament, and would turn off when the high beams were turned on (in certain markets). At least this is my understanding. My only experience is with my 1990 sealed beam car.

[e30owner]

Thanks for the reply. Maybe I should try removing fuse#1, which protects the left hi-beam circuit, and see if it affects just the H5001 headlight, or both the H5001 and H5006. Would that tell me anything?

[hankolerd]

I won't claim that I know one way versus the other, but I will say I was basing my knowledge off of this wiring diagram (from http://users.rcn.com/nifftylion/head...%20-%20Pub.pdf), which shows:
1) High beam relay is always hot (even when the car is off), but the high beam switch can only enable the high beam circuit when in run/start.
3) Low beam relay is hot only in run/start
2) Low beam circuit goes hot when in run/start AND headlight switch is in head position, to power the low beam filament in the low beam bulb.
4) Low beam relay power is cut when High beam relay is switched on (Entire low beam circuit goes cold)
5) High beam circuit has a crossover AFTER the fuse's directly to the high beam filament in the low beam bulb

[e30owner]

Maybe I'm misinterpreting this wiring diagram, but aren't there separate 7.5A fuses for each lo-beam bulb and each hi-beam bulb?

Fuse 1 7.5A Left hi beam
Fuse 2 7.5A Right hi beam
Fuse 13 7.5A Left lo beam
Fuse 14 7.5A Left lo beam

Doesn't that mean that each bulb can draw up to about 90 watts?

[hankolerd]

Thanks for the detailed report. I don't know much about headlights, but I own a 1986 BMW 325 with stock H5006/H5001 sealed beams. i notice that according to the above specs, the Hella mixed Lo/Hi unit is an "exact replacement" for the H5006 sealed beam. The H1 bi-focus Lo-beam, on the other hand, is intended as a replacement for 4002 and 4005 sealed beams, which I do not have. Does that mean that replacing my H5006 sealed beams with the H1 Bi-Focus Lo-beam unit would give superior lighting, but would require modifications, whereas replacing the H5006 with the H4 Lo/Hi would give up some light, but would be plug-and-play?

That is correct.

EDIT:
However, the H4 Hi/Lo kit pulls more wattage than the H5006 when in high-beam mode (55W vs 35W), so you would need to protect the high beam circuit with a 10A fuse instead of the 7.5A, assuming you are still running a 50W high beam. The high beam load would be (55W+50W)/12.8V=8.2A, where the stock load is (35W+50W)/12.8V=6.6A. If you upgrade the high beam to a higher wattage you may need even a bigger fuse. Depending on how much you trust your wiring you may want to run larger gauge wires. It seems a lot of people have gotten by with a 10A fuse OK, but that doesn't mean it doesn't increase the risk of an electrical fire.