Why is there a relay on my headlight?

[K Simmonds]

Yeah, the light's are pretty good on both my car's, dip can be a bit crappy when it's wet or foggy but their perfectly acceptable so I'm keen to see what their like when given full voltage.

[John.]

Yeah, the light's are pretty good on both my car's, dip can be a bit crappy when it's wet or foggy but their perfectly acceptable so I'm keen to see what their like when given full voltage.

It'll only make it more enjoyable to drive!!

[K Simmonds]

Indeed! I have plenty of suitable relays knocking about so no excuse really.

Just remembered, if you do yours John it would be wise to keep an eye on how hot your higher wattage bulbs get. I know with Corrados that relayed high wattage headlight bulbs can give off enough heat to damage the reflectors...not sure if that's the case with our cars though...

[John.]

Indeed! I have plenty of suitable relays knocking about so no excuse really.

Just remembered, if you do yours John it would be wise to keep an eye on how hot your higher wattage bulbs get. I know with Corrados that relayed high wattage headlight bulbs can give off enough heat to damage the reflectors...not sure if that's the case with our cars though...

Aye, know what you mean. My reflectors are slightly mis-shaped but I have yet to see a B3 that has perfect reflectors?
.......over to you Noel! What's your reflectors like?

[Nj]

still haven't managed to check yet John. currently on another business trip, writing from a train because work got in the way
Back tomorrow night so I'm intending to find out on Saturday morning.

[Nj]

Turns out it wasn't the reflector. It was the brand new nightbreaker bulb.
This is what it looked like with the dodgy bulb in. The surface of my garage wall doesn't help matters but you can kind of see.


I put one of the old bulbs back in and it's not as bright but at least the beam pattern is right.

[K Simmonds]

Having had my S2's dip beam switch give up this week I'm going to get on the case and relay my headlights this weekend to take the load of the replacement and have much better lights.

I have ellipsoids fitted with the pin swap mod done and it's clear from the colour of the pin it's been getting too hot.

[quattrodave]

I did this mod to the standard twin headlamps on my 93 2.6 80 avant quattro, did a pre and post voltage check on the bulbs and although I took both the + and - feed direct from the battery not the alternator (wanted to be able to get to the inline fuses in event of a problem and they are now hidden under the battery cover behind the passenger headlamp) as the rear of the alternator is not easy to reach.

I;m now getting at the bulb within the headlamp

Passenger
+ Low beam = 13.76 (was 12.48) high beam = 13.36 (was 11.54)
- low beam = 13.89 (not measured before) high beam = 13.56 (not measured before)
Driver
+ Low beam = 13.5 (was 12.41) high beam = 12.95 (was 11.26)
- low beam = 13.83 (not measured before) high beam = 13.5 (not measured before)

I noticed a big improvement in light output immediatly on standard osram 60/55W H4 and 55W H1 bulbs. The driver side is slightly lower on voltage as the wiring run is a bit longer.

However, I decided to do a post wiring test on the low beam with a light meter and alternative H4 bulbs as I have a few lying around. Measured from passenger headlamp only at a distance of 6 feet (approx 1.8 metres for the youngsters). Ignore the actual lumens the important thing is the difference.

Standard Osram H4 = 750 lumens (55 watts)
Mtec diamond white 4150k H4 (supposed to output 130/110 watts using 60/55) = 740 lumens (55 watts supposed to be equal to 110 watts !)

Nightbreaker plus H4 = 1120 lumens (55 watts)

Cheap 100/80 chinese H4 = 1060 lumens (80 watts just about equals the nightbeaker)

Autobulb 160/100 H4 = 1350 lumens (100 watts)

I also measured a cheap 100 watt H1 I had previously put into the main beam without the H4 connected and it gave 3000 lumens, when I also had the H4 connected up (running on main beam only as I have not done the wiring mod to leave low beam on as well) I recorded 4500 lumens in total with the nightbeaker plus H4 (60 watt on high) and the cheap 100 watt H1.

Food for thought, but on the road with the 160/100 H4 low beam its really good on low beam now, I;m awaiting delivery of a 130 watt H1 to complement the 160 watts of the H4 high beam and I'll also do the wiring mod to keep low beam on when on high so hopefully on high beam with my new upgraded wiring I can give the HIDs in reflector boys some reverse medicine when they come towards me with their light up everything glaring headlamps. (doing the maths each light will output 100 +100 +160 = 360watts x 2 on high beam) just won;t be able to keep high beam on for long as I might melt the reflectors.

Yes its technically illegal to use high power bulbs without e marks but it will still pass an MOT unlike an HID conversion in reflector or projector lamps.

What I need now is one of the H4 leds to do a further comparison but they are still pretty expensive.

[Nj]

Do all B3 and B4 chassis 80 & 90 chassis cars have H4s for dipped and H1s for main beam?

[Mikes2]

Only the elliposoids which use H1 / H1 are different

[LHD_Kid]

Yes its technically illegal to use high power bulbs without e marks but it will still pass an MOT unlike an HID conversion in reflector or projector lamps.

Interesting complete post above, thanks for sharing...

In honesty, I've never had any issues - or even been questioned regarding passing the MOT with HID converted projector lamps (ellipsoids).

The headlight washers work and they are manually adjustable for height. MOT tester appears to take it that automatic adjustment (if fitted) must work, if not fitted, manual adjustment is acceptable...

[Nj]

Only the elliposoids which use H1 / H1 are different

Good to know, thanks Mike.

[K Simmonds]

I did this mod to the standard twin headlamps on my 93 2.6 80 avant quattro, did a pre and post voltage check on the bulbs and although I took both the + and - feed direct from the battery not the alternator (wanted to be able to get to the inline fuses in event of a problem and they are now hidden under the battery cover behind the passenger headlamp) as the rear of the alternator is not easy to reach.

I;m now getting at the bulb within the headlamp

Passenger
+ Low beam = 13.76 (was 12.48) high beam = 13.36 (was 11.54)
- low beam = 13.89 (not measured before) high beam = 13.56 (not measured before)
Driver
+ Low beam = 13.5 (was 12.41) high beam = 12.95 (was 11.26)
- low beam = 13.83 (not measured before) high beam = 13.5 (not measured before)

I noticed a big improvement in light output immediatly on standard osram 60/55W H4 and 55W H1 bulbs. The driver side is slightly lower on voltage as the wiring run is a bit longer.

However, I decided to do a post wiring test on the low beam with a light meter and alternative H4 bulbs as I have a few lying around. Measured from passenger headlamp only at a distance of 6 feet (approx 1.8 metres for the youngsters). Ignore the actual lumens the important thing is the difference.

Standard Osram H4 = 750 lumens (55 watts)
Mtec diamond white 4150k H4 (supposed to output 130/110 watts using 60/55) = 740 lumens (55 watts supposed to be equal to 110 watts !)

Nightbreaker plus H4 = 1120 lumens (55 watts)

Cheap 100/80 chinese H4 = 1060 lumens (80 watts just about equals the nightbeaker)

Autobulb 160/100 H4 = 1350 lumens (100 watts)

I also measured a cheap 100 watt H1 I had previously put into the main beam without the H4 connected and it gave 3000 lumens, when I also had the H4 connected up (running on main beam only as I have not done the wiring mod to leave low beam on as well) I recorded 4500 lumens in total with the nightbeaker plus H4 (60 watt on high) and the cheap 100 watt H1.

Food for thought, but on the road with the 160/100 H4 low beam its really good on low beam now, I;m awaiting delivery of a 130 watt H1 to complement the 160 watts of the H4 high beam and I'll also do the wiring mod to keep low beam on when on high so hopefully on high beam with my new upgraded wiring I can give the HIDs in reflector boys some reverse medicine when they come towards me with their light up everything glaring headlamps. (doing the maths each light will output 100 +100 +160 = 360watts x 2 on high beam) just won;t be able to keep high beam on for long as I might melt the reflectors.

Yes its technically illegal to use high power bulbs without e marks but it will still pass an MOT unlike an HID conversion in reflector or projector lamps.

What I need now is one of the H4 leds to do a further comparison but they are still pretty expensive.

Lot's of good info there, thanks for taking the time to write it all up

[Bowie69]

Yep, very helpful, thanks!

So taking that, and wanting to remain legal, Nightbreakers come out really well.

[quattrodave]

For info I believe I gained about 38% more lumens by doing the conversion as previously I was gettung a max of 12.5v at the bulb now I'm getting around 13.5-13.75 at the bulb, I figure this out from the daniel stern site which shows how lumens increase/decrease against available voltage - link below

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

The change to nightbreaker plus H4 added around another 40% extra light so the difference to standard wiring is even more dramatic as doing the maths I'm now around double the light ouput I had originally, the further step to 160/100 H4 gave me 20% more light than the nightbraker plus so I'm now around 2.4 times more lumens than on standard bulbs and standard wiring.