Help newbie understand dim headlights

[jav]

Hi folks-

first post- be gentle.

I recently bought my duaghter a 2000 NB TDI. I noticed the low beams were very dim (but working) and have been searching like crazy to understand the problem. I am now thoroughly confused.

I've read a ton of different explanations but they fall into one of the catagories below and I don't know what to believe?

1) there are 2 filaments in the low beam bulb 1-drl - 1 low beam & there should be an intensity difference in the drl to low beam output. If there isn't- it could be fused filament (bad bulb), fuses, relay, wiring or switch problem.


2) there is 1 filament in the bulb and only a minor voltage difference to the filament with very little difference in output.

3) the low beam and drl are one and the same (no difference in intensity)- if it works but it's dim- replace the bulb.

4) Not electrical but lense related - this doesn't seem to be the case with ours but the projector lens in front of the low beam (not the outter plastic lense) does not seem clear?

Help??

[2004NBTURBOS]

First off,Wecome to the Org
Not sure if this helps. But in both of my NB's, the DRL and the low beam have the same output. If I were in a dark place, say my garage, and start the car and disengage the parking brake, the DRL's will come on. Now when I switch on the headlights, the light intensity is the same, but the other lights come on, tails side markers, etc. As stated this was like this on both of my NB's, and I put over 100k on each.
Are they so dim that it has become a issue where you have trouble with visibility at night? Or are you wondering the difference between DRL vrs low beam? These bulbs start to wear over time, so it may be as easy as changing the bulbs. Make sure not to touch the bulbs as you replace them. The oil in your skin can cause the bulbs to fail early.

[jav]

Thanks for the welcome and great forum!!

No- the dim lights are a very real issue. Also- i should have mentined that I'm very handy with a wrench and do understand safe handling of the bulbs but thanks for the heads up. We took the beetle out last night and at times, I wondered if the lights were on at all. I could hardly see any illumination 30-40 feet in front of the car.

We got home and facing the garage door- we could clearly see the low beams working- as were the high beams, but the low beams were extremely diffused. By diffused I mean there was just an even glow on the door, there was no clear bright spot that I'm used to seeing for aiming the light. For the high beams there was clearly a higher intesity region of focused light but the low beams just seem to glow- no focus at all.

It looked to me like the inner projector lens was frosted and that's what prompted me to search on NB low beams and then the confusion started.

I must admit that on my jetta- I see no difference in intensity from DRL to low beam BUT the DRL AND low beams are about 4 times brighter than the beetles.

I really just want better low beams on the beetle and the onyl reason I bring up the DRL vs Low beam is so that I can perform an appropriate repair. If there's "supposed" to be a difference as many sources suggest, then I'd want to fix it. I kind of doubt that there is becasue I've found low beam fuses but no DRL fusing. This, to me, suggests a single circuit whereby fuses can be eliminated IF there is either low beam or DRL working. But then you find numerous thread about folks losing low beams but not DRL and then having some fix (bulbs, headlight switch, non factory approved fix)

I guess I just wnat to understand, for certain, how it's suppose to work so I can go about fixing it properly.

[IndyTom]

The DRL's work off the Low Beams at reduced voltage. They are on the same circuit. How does your headlight lens look? The plastic over time does get cloudy and perhaps one of the many headlight restoration kits will help intensify your light output.
Have you tried just replacing the bulbs? It would be a cheap fix and something I would try first. The projector is suppose to be somewhat frosted and not clear so that is perfectly normal. You can try a higher intensity light bulb. I would stay away from Silverstars. They don't last very long and their light output isn't really that much better.
The Osram Nightbreakers are pretty decent bulbs but only available on Mailorder.
http://www.amazon.com/OSRAM-Night-Br.../dp/B004HUBEEK

[jav]

The beetle outter lenses are actually pretty clear. No restoration (polish needed). My O3 jetta lenses are actually more cloudy than the beetles but again- the jetta low beams are about 4x brighter than the beetles despite being behind cloudier lenses.

I'm reasonably sure my problem is the bulbs but what i'm not sure about is IF the bulbs are dim becuase their dying OR if they are dim becuase of some other electrical problem related to the DRL/Low beam transition- or even IF that transition exists.

[D2Beetle]

Off the top of my head, it might one of two things; the bulb to projector lens alignment may be off and/or the head light alignment may be off.

The assembly that holds the bulb and alignment mechanism is plastic and can crack/break; once it does the headlight cannot be aligned, nor does it project the light correctly.

If it were me, I would take the headlight apart and look it over for broken/cracked plastic parts.

[IndyTom]

Originally Posted by jav

The beetle outter lenses are actually pretty clear. No restoration (polish needed). My O3 jetta lenses are actually more cloudy than the beetles but again- the jetta low beams are about 4x brighter than the beetles despite being behind cloudier lenses.

I'm reasonably sure my problem is the bulbs but what i'm not sure about is IF the bulbs are dim becuase their dying OR if they are dim becuase of some other electrical problem related to the DRL/Low beam transition- or even IF that transition exists.

I would take out the bulbs and just swap them out with some Cheapo Sylvania Bulbs just to see if there is a difference. They are only 2-3 bucks a piece at Autozone. At least if the bulbs are still dim than you would have eliminated that. But hey, they may be just as bright as your Jetta Go for it.

As far as a difference between the DRL and Low Beams. I suppose there should be a slight difference since the DRL's run at lower voltage than the Low Beams. But personally, I have never noticed much of a difference. Now that I have HID's I have disabled the DRL's and only run the HID's at night.

Go swap out the bulbs and see what happens. All this speculation won't get you anywhere unless you actually try out some things.

[Smileybug]

There is a difference between low beams and DRLs...very slight, but there is.

[jav]

Originally Posted by IndyTom

I would take out the bulbs and just swap them out with some Cheapo Sylvania Bulbs just to see if there is a difference. They are only 2-3 bucks a piece at Autozone. At least if the bulbs are still dim than you would have eliminated that. But hey, they may be just as bright as your Jetta Go for it.

As far as a difference between the DRL and Low Beams. I suppose there should be a slight difference since the DRL's run at lower voltage than the Low Beams. But personally, I have never noticed much of a difference. Now that I have HID's I have disabled the DRL's and only run the HID's at night.

Go swap out the bulbs and see what happens. All this speculation won't get you anywhere unless you actually try out some things.

I guess I'm going to have to try the bulbs but I really hate doing that. I get upset when dealers just change parts without proper diagnosis and try not to do that myself. I was hoping to get a definitive answer on how the system is supposed to work then figure out which component(s) need to be serviced.

[jav]

Originally Posted by D2Beetle

Off the top of my head, it might one of two things; the bulb to projector lens alignment may be off and/or the head light alignment may be off.

The assembly that holds the bulb and alignment mechanism is plastic and can crack/break; once it does the headlight cannot be aligned, nor does it project the light correctly.

If it were me, I would take the headlight apart and look it over for broken/cracked plastic parts.

Great thought- I'll pull the lights and have a look.

[IndyTom]

Originally Posted by jav

I guess I'm going to have to try the bulbs but I really hate doing that. I get upset when dealers just change parts without proper diagnosis and try not to do that myself. I was hoping to get a definitive answer on how the system is supposed to work then figure out which component(s) need to be serviced.

LOL, that way you will keep analyzing yourself to death without ever getting anything done.
I could understand your logic if it were something major to replace but why not just pop in a couple of new bulbs and see what happens? It is easy enough to do and it might just fix your problem that you have been worrying about. If you don't start somewhere you will never get it resolved.
You are making this way to complicated. Just try the easiest solution first and then worry about what it might or might not be later

[IndyTom]

Originally Posted by jav

Great thought- I'll pull the lights and have a look.

Excellent idea! and while you are in there swap out those old crappy bulbs for some nice fresh ones and see the light

Serioulsy, Good Luck! I know these things can be very frustrating.

[Duffy]

The correct hi and low beam headlight bulb is H1. This is a single filament. You may have the incorrect bulb installed if it has two filaments.

[janitz]

Originally Posted by Smileybug

There is a difference between low beams and DRLs...very slight, but there is.

Very slight.

I think if you lived in the city you'd never notice. It was very dark this morning and I turned them on/off to see, and it's only a very slight drop in light output.

Also, it should be noted that the older a bulb is, the less output it has, so combine age with possibly other factors and it could explain the dim lights.

[Duffy]

DRL's and low beams are one and the same. There is no difference in voltage applied to them. The DRL relay just drops out the low beams when the E-brake is pulled up one notch. Not sure what year the DRL relay started, it doesn't appear on the 2000 wiring diagram.

[Smileybug]

There definitely is a difference. I saw it when I would start my car in the dark before I turned on the headlights. They would get the slightest bit brighter when I did that. Again, its slight, but there is a difference.

[IndyTom]

Originally Posted by Duffy

DRL's and low beams are one and the same. There is no difference in voltage applied to them. The DRL relay just drops out the low beams when the E-brake is pulled up one notch. Not sure what year the DRL relay started, it doesn't appear on the 2000 wiring diagram.

Here is a link that shows the location of the DRL 173 Relay.

Disabling Daily Runing Lights (DRL's) - How-To

I have a 2000 Beetle and I haven't checked to see if I have a 173 Relay or not. I saw on some forums that they didn't use that relay until 2001.5 VW cars.

So are you saying that the same voltage is applied to the DRL and the Low Beams? So there really shouldn't be a difference in brightness then, right??

[Duffy]

Correct, the low beam brightness (applied voltage) does not change in relation to the DRL function. If brightness variations are observed, its only due to system voltage changes. As things are turned on or engine speed changes, slightly effecting alternator output, and condition of battery generally are the causes. Not to mention old and/or resistive connections.