Poor main beam lights

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adamm

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Hi there, wonder if anybody can shed some light on this one for me (excuse the pun). Having been forced to use the CSi this week whilst the 02's off the road I've noticed that the main beams (not full beams) aren't what they used to be and aren't even as good as the lights on my 02 - and that's saying something!

The lights look bright enough when you look at them from the front but they throw nothing onto the road and it's a bit scary when a car comes the other way and you have to dip from the full beams - suddenly darkness!

I had a little search but didn't turn up anything relating to this particular problem - is it something to do with the main beams being unrelayed/unfused?

The lights themselves look to be in good condition still, nice bright reflectors so I don't think it's that.

Any thoughts most appreciated, adam
 
It's probably less to do with the relays and more to do with old wiring and connections. As time takes its toll on the wires and insulation, resistance in the circuit builds up and voila, no light for you. Here's your chance to rebuild the circuit (oh boy!) properly. A good read on the topic that explains how to measure the voltage drop you're experiencing and what to do about it:
http://www.danielsternlighting.com/tech/relays/relays.html
 
This might seem like a stupid suggestion adam, but are your lights actually pointing at the road? I only ask, because shamefully after owning my e9 for nearly 3 years i finally got round to re-adjusting the front lights into the correct position the other day. I hardly ever drive at night so it took me nearly 2 years to notice there was a problem.

Looking at the front of my car the lights looked bright but not dazzling, but when driving there was no light on the road at all. I fiddled around with the positioning and they now light the road instead of the trees!
 
Hi James, that doesn't sound so stupid as, like you say, the lights look bright enough, just nothing on the road. I'd rather fiddle with that first before going the re-wire route. I'd just assumed that the lights wouldn't have passed the MOT had they not been throwing the correct light. Like you I've never really driven the car after dark but if I'm going to continue to do so I need to sort them - they're terrible!

Thanks for the pointers
 
While on the topic of simple, it is worth pointing out that:

1. A weak alternator (brushes or regulator) can product low voltage and reduce light output a great deal. Often this will manifest as brightness varying with engine speed.
2. If you drive a car with HIDs, going to a car with sealed beams is like turning out the lights.
3. Sealed beams do deteriorate with time. If they are more than 5 or so years old they should be replaced. There are many reasonably priced 50w and 100w halogen options.
4. Light adjustment is pretty easily gauged by shining them on a wall from a flat surface (find a building and a flat parking lot). I suggest bringing along a reference car that has lights which seem fine to you. You can compare brightness and pattern / elevation. Adjustments are usually only needed after replacing bulbs or straightening sheet metal after a wreck.
5. Take off your shades. You look cool enough in your coupe as it is. 8)
6. Compound all the above with 35+ year old wiring and you have dim lights or at least the feeling that you have dim lights. :p
 
...weak alternator

Would a weak alternator also make my horn sound a muffled fart; or is that the horn, a ground, or contact on the steering wheel? Thanks, Dave V. in NC
 
Not likely. Horns tend to rust (surprise)!

The contact in the steering wheel only completes power to the horn relay; so if the horn does anything the relay path is most likely working. The relay could be bad but usually they just fail due to contacts breaking or burning. The horn (I am pretty sure) is grounded by the bolt that holds in in place. This leaves three probable problems in what I would consider to by rough order:

1. The horn is rusted (it may blow clear)
2. The horn bolt is rusted (ground)
3. The power to the horn is weak
--- A burned relay contact
--- Frayed wires.

The horn draws considerable current. Probably 15 amps to start and then 5-10 to stay honking.

I would recommend trying to bypass everything and potting 12volts directly on the horn. You can do this with some heavy wire connected to the positive battery terminal (be careful of arcing). Alternately you can pull the horn and use jump cables (one on bolt the the other on the power lead). If you do this secure the wire or jumper cable to the positive battery terminal first and have the horn somewhere farther away; the arcing can be dangerous near an old battery.

It is possible the in doing this you will get the horn to start working again. Sort of like an Italian tune up! The act of honk is a bit violent inside the horn; the vibration can actually make the rust fall off. Personally I might consider this to be an great excuse to upgrade to some big air horns (also period correct)!
 
Horn

One of my horns did not work so I bought two Hella replacement horns. They were only $7 or 8 each, are red and a little smaller but with the same attaching arm and are much louder (at least I think they are!). My horn contact at the wheel is another issue. It is a little spring/wire/contact that inserts from behind the column but it doesn't stay tight and gradually loosens so the tip does not contact the horn ring eventually (I have a Nardi BTW).

Also, it isn't often that one comes across flat headed screws in a BMW or other cars for that matter, but the panel under the column is held on by four of these. Since I hadn't bothered to look, I couldn't figure out why the phillips screwdriver couldn't find the screw head.
 
Farting horn--may be due to lack of functioning ground

on one of your horns, the one that works and other doesn't that gaseous sound may emerge--

here is my guess--each horn has a different tone from the other and proper operation depends on both working together to give correct (non-farting) harmonious sound--would suggest having your partner touch horn when you are pressing the button--should be able to "feel" the one that is non-op.--since your car has just been painted there is a good possibiity one is not properly grounded.

I always felt sound level of original horns was similar to a sick sheep bleating so--disabled them--left them in place and installed twin trumpet bright red Italian air horns as their replacement--from Mesa Performance--now gives off nice sharp alert.

Did same for my 2002--although with triple red trumpets due to greater available space available for mounting same--gives the little guy some real ability to alert those errant or sleepy or just thoughtless drivers with a nice jolt--and it helps celebrate the Italian heritage of our elder BMW's Italian design input for both.
 
Weak headlights

Whoa! Before doing any major work, check the grounds. The factory ground connection for the headlights is pretty poorly engineered. Certainly it was never designed to still be functioning 35 years down the road!

Clean off the old rust behind where the ringlugs attach to the bodyshell. If your car has been repainted, clean off some paint too (bodyshops don't seem to understand that electricity doesn't flow through paint!). This simple fix did a lot to improve the brightness of my headlights.
 
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