New Hella lights, blew fuse - what'd I do?

[LateFan]

Put a set of Hella H4 outer h-lo lights in. Soon after, both left side lights went out when I flipped to high beam. Both rights stayed on.

Checked fuses, #1 7.5A was burned. Replaced, everything works fine.

Ideas on what happened? Tired old fuse with new current? Sketchy turn signal / flasher switch on the column? It's kind of loose.

Thanks -

[Das Delfin]

You need to change fuses 1 and 2 to 10A

Mine didn't blow when I did H4's but I swapped them to 10A anyway

[AndrewBird]

DO NOT SWAP TO HIGHER AMPERAGE FUSES!!!

The fuses are rated for the wiring in the circuit. Putting a higher amperage fuse in will put a higher load on the wiring and can cause it to heat up, melt and/or start a fire.

Did you change any of the wiring, or just install the lights?

[LateFan]

^ Agreed - that's asking for trouble. It blew again the next time we started it and flipped on the brights. The lows work fine and are on. #1 runs the left side highs and #2 the right side highs?

We only swapped the outboard headlights. Didn't touch anything but the outer headlight plug. They're standard Hella 60/55 bulbs. They wouldn't draw any more power than a standard sealed beam, would they?

His signal / flasher switch is a little wonky - maybe the mounting screws are loose or the plastic is broken? Need to pull the shrouds and take a look.

[LateFan]

[ATTACH]110419[/ATTACH]

[Das Delfin]

omfg. Please read this article before talking shit about higher amp fuses. It's great that you know a lot. But there is more for you to learn. You can't just make a general statement about wiring. While yes, you are correct in general, you need to take that argument and consider the wiring that is actually in the bmw.

You have to take into consideration the gauge of the wire. The larger diameter of the wire, the more current it can handle. Read page 9 of this article

http://www.billswebspace.com/E30LightingConversionInformationXMon.pdf

Actually I'll quote it for you

"A note about further wiring modifications:
The headlight wiring in the E30 is sufficient to handle up to twice its sock current, 15 amp fuse versus the stock 7.5 amp, WITHOUT any risk of damaging the wire. This would allow you to run up to at least a 110Watt bulb without having issues with the lighting, and the voltage drop at the light should be minimal."

[Das Delfin]

also, if you did any kind of research, you would know that a low/high sealed beam puts out 35w on both sides. So two 35w plus two 55w for your inner highs = less current than four 55w bulbs using H4... this is why it blows the fuse. Did you not look into this at all before going for it?

also also, putting a higher amperage fuse won't put any more of a load on the wiring. You understand that the light puts a load on the wiring, and the fuse just offers a cap in case for whatever reason the light blows and somehow shorts the wiring? So four 55w bulbs = 110 w on each side (since there is a separate fuse for L and R) and 110w at 13v = about 8.5a, which is why it blows a 7.5a fuse. However, if you put a 10a fuse in, you are still okay because the wiring doesn't melt until twice its rated amperage (aka 15a).

This is why putting a higher wattage bulb is less safe than upping your fuse. Yet it is mistakenly more acceptable. Why? Because people aren't aware of the whole story.

[AndrewBird]

What you aren't realizing is you do not want to run your wiring anywhere near it's limit. Generally a safety factor of 40% is used. So a 7.5A fuse is used on wire that can handle 15A (50% factor in this case, but that's only because you have to step up to the next gauge wire).

And yes, the bulb is what puts a load on the wiring, but the fuse is what protects the wiring FROM these loads. The fuse is doing exactly what it was meant to do; blow when a higher than normal load was put on the wiring.

Just because you can and people "do it all the time" does NOT make it safe to do. Putting a higher wattage fuse in place is NEVER safe.

OP, you need to run new relays with higher amperage wiring if you want to safely use higher wattage bulbs.

[LateFan]

Actually, no, I didn't look into this before I bought them. I've had quad 5 3/4" Hellas or Cibies on several cars in the past and they were plug-in-&-drive, no problems. Alfa, Volvo, Scirocco, a Ford Capri...

These were on sale for a screaming deal at ipd (the Volvo parts guys) so we grabbed them.

So, my biggest question is - these are German sedans designed to operate in Europe without stupid US sealed beams, so why is the lighting circuit designed to not handle anything more than 35w lights?? They would have had Hellas or smilies or some kind of quartz lights over there. Are the US cars wired differently?

Here is the Daniel Stern (whom I've dealt with before) write-up on installing relays on aftermarket lights.

http://www.danielsternlighting.com/tech/relays/relays.html

Is there a more-E30 specific or simpler version DIY here in the lighting section somewhere? A brief search didn't find it.

BTW, a Cibie H4 is a far better light, but usually at double to three times the price.

[LateFan]

So, here's an old thread where the Great FredK weighs in on the H4 issue...

"That's true, if you just increase fuse size without calculating anything, you'll run into problems.

If you are installing Hella H4/H1 in the place of stock sealed beams, you need to increase Fuses 1 and 2 to 10A. It has to do with the power switching arrangement. In a sealed beam car, the low beam has two filaments. On low, Fuse 13/14 supply the power. When you flick the highs on, it lights both the high beam AND the second filament in the sealed beam through Fuses 1 and 2.

When you have a 55W/60W H4 bulb and 55W H1 bulb lit, you have a demand of 115W on Fuse 1 and Fuse 2.

P=IV and if P=115W, V=12V, then I=9.6A. So you need a fuse with a rating of >9.6A. That is why you need a 10A fuse."



So, I don't get that he's saying both the filaments in the outboard light stay on when you hit the highs. My understanding is that the outer low beam filament goes OFF when the highs come on - wasted light going to the wrong place, too much heat, etc.

Is the E30 circuit designed so that BOTH filaments stay on? If so, then no wonder it blows the fuse.

Full disclosure - I'm not that sharp with those electrons.....so tiny and hard to see.


EDIT for reading comprehension -
He never says both outboard light filaments are on at the same time - he says both the inner high beam and the outer high beam are on. That doesn't imply both filaments in the outboard light are on. I have seen people try to jack the wiring so they DO, however. Not the point here.

[Das Delfin]

The wiring used in our old bmws is generally of much higher quality than newer cars. Overbuilt, some would say. This is why it's acceptable to run it at 60% of its capacity (9.6a current draw over a total of 15). Because it's overbuilt.

I don't see why BMW would have used lesser quality wiring in their US cars since most of our cars came optioned way up and placed high in the market. It would be much more expensive for them to make their tooling and machines to deal with two different versions of cars more than absolutely necessary. They saw US bumpers as an inconvenience - why would they make more work for themselves by making entirely inferior wiring harnesses? Why would they contract for thinner gauge wire for their cars which are to be sold as luxury models? Especially in the day when every sport model and most convertibles came with an LSD standard.

As far as which bulbs come on, it works like this: The inner bulbs have one filament, but the outer bulbs have two. Sealed beam units are 35W/35W, but the high beam 35W is placed within the reflector in such a way that it has different optics, which throw the light higher up. Thus "high beam."

Hella H4's are 60W low and 55W high. You might think it's crazy that the "low beam" has a higher wattage, but it really all comes down to the placement of the filament within the focal point of the reflector.

So when you turn on your high beams, it turns off your low beam, and then turns on the inner high beams, as well as the high beam filament in your outer headlights. This is why you have 110W on each side: because there are four 55W bulbs.

This is also why you have three leads for the outer lights, but only two leads on the inners. The inners have hot and ground, while the outers have ground, hot for low, and hot for high.


One really cool thing you could do is grab a pair of Hella BiFocals - these are 55w low beam only headlights that were designed as a joint venture between Hella and BMW for their cars int he 80's. It's super period correct for an early model and not many people know about them. Plus the optics of a low beam-only headlight are superior to that of an H4 - when a headlight only has one job, it can do that job very well.

When I switched from H4's to ellipsoids, I noticed my high beams weren't as bright (having only two instead of four high beams) but I was able to aim them in such a way (and change the wiring so that my low beams stayed on with the high) so that it didn't matter. Something to consider if you are worried about light output.


But in the end it comes down to this: If you want to run Hella H4's, as many people have done and have not had a problem with, you have to upgrade the fuse for it to work. Or you have to completely rewire your headlights. But no one wants to do that. Plus the copper in wire you are going to find nowadays is going to be of inferior quality than what was originally in your bmw.

One thing you could do is unplug your high beams - then you would only draw 55w on fuses 1 and 2, but you would still have good output from the H4's. Again if you're paranoid. I ran H4's in my car for a year with no issues before grabbing a set of ellipsoids.

[Mo Brighta]

Headlight woes

OK, seems like we are on the right track, several true statements from all.

Relays - present, usually rated 30 amps (entirely adequate for headlights), and for the same reason as wiring standardization - simplicity of part stocking. US Sealed Beam and Euro H1 / H4 lights use the same relay power switching scheme, it's when you go to ellipsoid or BiFocal (single purpose) low beams that the scheme changes.

BiFocals - Yes they are fabulous, expensive, but definitely worth it if you want to light up the road WITHOUT blinding oncoming drivers. Aimed well, of course, and with clear headlight film (cheap insurance) to prevent damage. Mine took a pickup's back bumper at low speed and survived unscathed. Thanks goodness - they are CSR, which are NLA.

Hella H4 standard lamps - you can do much better, lots more light for (here's the good part) the SAME WATTS as standard lamps.

Elipsoids- same thing applies to your ellipsoids Delphin, much better off with 9012 lamps, nearly 100% brighter, SAME WATTS as stock HB4. Ping me if you want a pair. They're getting cheaper!

Fuses - Yes, they get weak, they fail, they have 'rating creep' (increased failure current with age), AND they are cheap enough to replace as preventive maintenance every 3-5 years. Keep a few of each rating in the tool kit as emergency spares, of course.

Wiring - Yes, older wires are generally thicker. Any of the BMW headlight wires should handle ten amps easily, with the weak link being the ground wire, it carries current from all filaments. In general, it's good fuse advice - bumping up amps should be done only (1) after it's been determined safe, (2) when absolutely necessary, and (3) after other options have been explored and appropriate steps taken.

Electrical failures are usually at the connector / termination, not in the middle of a conductor run. A dead short with amperage that causes the wire to glow red is unlikely with any fuse in the circuit, both 7.5 and 10 amp will fail long before 'you let the smoke out' of the wiring.

Now, the original issue was the fuse blew on the left side, stated to have happened once with high beams. Questions-

does this happen each and every time you use highs?

have you checked the bulb connectors after running the lights for 10-20 minutes for *overheating*? (compare left/right for similar temp.)

do connectors slip onto lamps with little resistance, or does it take a good shove? This is a weak point, and can usually be solved at no cost.

I'd say a good close inspection of all connection points in the circuit will locate any real problems, and if you are like me, use a magnifier as needed. And don't overlook the headlight switch on the column, they are a known weak point that gets lots of abuse.

A test light is a good tool to have on hand, as is an ammeter.

LateFan - look for an email.

[LateFan]

OK, seems like we are on the right track, several true statements from all.

Hella H4 standard lamps - you can do much better, lots more light for (here's the good part) the SAME WATTS as standard lamps.

With a different lamp in the Hella housing? (I realize these aren't the best output, and I've read D Stern, but it's not my money I'm spending) Also, the first car I put a full set of four expensive lights in as a young punk - a week later a guy backed up into me at a stop sign (?) and mashed all four. So we're being frugal.



Fuses - Yes, they get weak, they fail, they have 'rating creep' (increased failure current with age), AND they are cheap enough to replace as preventive maintenance every 3-5 years. Keep a few of each rating in the tool kit as emergency spares, of course.

Have a bunch of extra new ones.


Wiring - Yes, older wires are generally thicker. Any of the BMW headlight wires should handle ten amps easily, with the weak link being the ground wire, it carries current from all filaments.

Is this the ground point behind the drivers side headlights? All four lights ground here?


In general, it's good fuse advice - bumping up amps should be done only (1) after it's been determined safe, (2) when absolutely necessary, and (3) after other options have been explored and appropriate steps taken.

A dead short with amperage that causes the wire to glow red is unlikely with any fuse in the circuit, both 7.5 and 10 amp will fail long before 'you let the smoke out' of the wiring.

The Lucas smoke?!


Now, the original issue was the fuse blew on the left side, stated to have happened once with high beams. Questions-

does this happen each and every time you use highs?

After I swapped in a new 7.5A fuse, it worked fine through several (6-8?) flips to brights. I parked it, and the next time we started it, on the second bright flip, it burned out again.


have you checked the bulb connectors after running the lights for 10-20 minutes for *overheating*? (compare left/right for similar temp.)

Will do this next.


do connectors slip onto lamps with little resistance, or does it take a good shove? This is a weak point, and can usually be solved at no cost.

A decent shove. Old ones came off very hard - I did a little careful prying.


I'd say a good close inspection of all connection points in the circuit will locate any real problems, and if you are like me, use a magnifier as needed. And don't overlook the headlight switch on the column, they are a known weak point that gets lots of abuse.

OK, will do next. His headlight switch is wobbly from whacking it - possible it is broken and shorted to the column. Car is at school, but will be back this weekend. We have a good multimeter and he's pretty good with it.

Question on the aging fuses - do the relays get weaker over time? It is an electrical switch, no?

Thanks for the ideas everyone. Appreciated.


- I should probably add that while I was fiddling with putting in headlights, he was under the car testing all the ABS wheel sensors and trouble-shooting ABS problems, so he's doing the majority of the work here. The last time I touched anything electrical on his car, I fried his instrument cluster and had to find a good used one! So ask me about anything electrical you need!

[Das Delfin]

The solder joints inside relays get weak. As far as the electro magnet, I'm not sure.

Mo Brighta, I'm running ellipsoids with H1s (with lamin-x). Thinking of doing a mini H1 HID bi-xenon conversion but it's not really a priority right now. Bi-focals are on the radar.

Fuse 1 controls the left side high beams, which each have their own ground wire. So each ground wire would only be running 55w each. If you were to use an electrical diagram to see where these two wires meet, where would that be? At the relay? Ie where is the weak point? So trace the signal from the headlights back.

[LateFan]

OK...
There is a ground point at the left inner fender wall (on an '86 anyway) just outboard of the ABS pump. It has four headlight grounds and a large ground from the ABS.

I cleaned it and all the contact surfaces, and the left light plugs. Put in another 7.5A at #1, and the lights worked fine. I let it run with the brights on to check temp per Mo's test, and after about 5 minutes the fuse blew. Never touched the signal stalk, it just sat idling.

So it's not an instantaneous blow, like a short would do. Doesn't feel like the column switch since I didn't touch it. I'll still take it apart to check it.

Does that sound like normal - too many watts and eventually the fuse heats up?

The relay (2nd one from windshield, passenger side) is a silver can instead of the light blue ones, Bosch 12V. 20/30A, 0332204401.