Halogen Headlights

esray

esray

Member
Here I go again!

I have just plugged my new halogen outer dip/headlights in. They really are such an improvement over the sealed beams, which had become blackened with age!

They look great on dipped, but when I go to main beam, the L/H outer fades to a glow - I mean not even as bright as dipped? All three other main lights are fine, as are sidelights etc??

I have checked all fuses for continuity....

Any ideas, please?

Ray
 
The halogens take much more current - make sure your alternator is healthy - a 75A alternator is a good companion to these lights.

What does the ammeter read when the main beam is on with the engine running?
 
raylish said:
Here I go again!

I have just plugged my new halogen outer dip/headlights in. They really are such an improvement over the sealed beams, which had become blackened with age!

They look great on dipped, but when I go to main beam, the L/H outer fades to a glow - I mean not even as bright as dipped? All three other main lights are fine, as are sidelights etc??

I have checked all fuses for continuity....

Any ideas, please?

Ray
Click to expand...
Hi Ray.

Not sure about your vehicle, but on mine you cannot have main and dipped on at the same time, unless you are using the flash facility, the main beam switch routes power to one or the other :?

A bit confused as well as you say they are fine on dipped, (so main beams will be off), but when you go to main it fades to not even as bright as dipped, (implying that main was already on).

If you mean that dipped are OK, but when switched to main, the bulb starts bright but dims on L/H outer only, then check the power connection to L/H main. On my diagram that shows a Blue/White from the bulb connected to a Blue/Green on the wiring loom. Have you tried swapping the L/H and R/H bulbs to see if the fault moves to the other side? If so the bulb is the culprit :x

Apart from that I would check the earth connections, they are normally the usual suspects, even if dipped works, (which I believe uses the same earth connection), the extra power taken by the main bulb, may be enough for it to make a difference.

I would clean all connections with a wire brush and some contact cleaner and try again.
 
they should take the same current unless you have gone to 100 Watt filaments, the usual culprit with headlamps is connectors and earthing.

Graeme
 
A poor earth or earths sounds like a possible suspect.

Work your way right through the headlamp earthing system and clean up all connectors. Pay special attention to the bullet connector receptacle (multi-way) which is buried at the front of the car behind the headlights on the offside IIRC. I replaced my receptcacle after the inside had turned to powder; they are available on the Vehicle Wiring Products website.
 
ethelred said:
The halogens take much more current.
Click to expand...

I've read this a few times so did some calculations and research.

The original lighting consists of a sealed beam unit of 37.5W/50W outer and a 75W inner unit.
This means on dip beam the power is 37.5 x 2 = 75W.
On main beam there is 50 x 2 plus 75 x 2 = 240W.
Using mean alternator voltage of 13.5V this works out to approximately 5.5A on dip beam and 18.5A on mean beam. I have no information on the light switch, or the dip switch, but would be surprised if either could handle the current of the main beam comfortably especially after 40 years.
Typical Halogen replacement are 55/60W.
This relates to dip beam being 55 x 2 = 110W and main beam of 60 x 4 = 240W.
Power consumption at 13.5 V equates to 8.1A on dip and 17.8A on main. So fitting halogens means dip power rising from 5.5A to 8.1A. This should still be within the limit of the switches. However both the 18.5A of the sealed beam units and the 17.1A of the halogens gives rise for concern.

The conclusion is that it is much safer to fit relays, especially in the main beam circuit, whether lights are upgraded or not.

The next question is it worth fitting halogens? The light output of incandescent sealed beam unit is typically 16 lumens per watt. Halogen lights give about 30 lumens per watt. When you consider xenon lights give 80 lumens per watt and some manufactures are now fitting LED headlights giving 100 lumens per watt, you can see why the original light look weak.

Sorry if this is a bit long winded, but I think it will be of use to some.

Jim,
 
Indeed. Nice one Jim.
One more reason to switch to halogens is that sealed beam units in our size are getting harder to find at reasonable prices.
 
A good summary Jim

Geordie Jim said:
I have no information on the light switch, or the dip switch, but would be surprised if either could handle the current of the main beam comfortably especially after 40 years.
Click to expand...

I had major issues with the headlamp and sidelight switch on Lady C suffering heat damage with the sealed beam units so fitted a relay.

Geordie Jim said:
The next question is it worth fitting halogens?
Click to expand...

I put off fitting halogens for ages as I deemed the light output from the sealed beams to be sufficient. However, as the days got shorter over the past few weeks I was really struggling to see the road ahead past the glare of the oncoming traffic so I fitted halogens. The difference is like night and day so I'd recommend anyone using their car regularly during the hours of darkness fit halogen replacements.

Dave
 
Geordie Jim said:
ethelred said:
The halogens take much more current.
Click to expand...

I've read this a few times so did some calculations and research.

The original lighting consists of a sealed beam unit of 37.5W/50W outer and a 75W inner unit.
This means on dip beam the power is 37.5 x 2 = 75W.
On main beam there is 50 x 2 plus 75 x 2 = 240W.
Using mean alternator voltage of 13.5V this works out to approximately 5.5A on dip beam and 18.5A on mean beam. I have no information on the light switch, or the dip switch, but would be surprised if either could handle the current of the main beam comfortably especially after 40 years.
Typical Halogen replacement are 55/60W.
This relates to dip beam being 55 x 2 = 110W and main beam of 60 x 4 = 240W.
Power consumption at 13.5 V equates to 8.1A on dip and 17.8A on main. So fitting halogens means dip power rising from 5.5A to 8.1A. This should still be within the limit of the switches. However both the 18.5A of the sealed beam units and the 17.1A of the halogens gives rise for concern.

The conclusion is that it is much safer to fit relays, especially in the main beam circuit, whether lights are upgraded or not.

The next question is it worth fitting halogens? The light output of incandescent sealed beam unit is typically 16 lumens per watt. Halogen lights give about 30 lumens per watt. When you consider xenon lights give 80 lumens per watt and some manufactures are now fitting LED headlights giving 100 lumens per watt, you can see why the original light look weak.

Sorry if this is a bit long winded, but I think it will be of use to some.

Jim,
Click to expand...
Hi Jim.

Whilst your figures are accurate, in theory there should be no problem with the switches ability to take the extra current.

On my 1972 3500S the fuses are rated at 10A each side for the 37.5W dipped, (with a halogen conversion taking just over 4A each side), whilst the 50W main beam outers fuse is 20A, and 75W inners is 25A, (halogens taking just under 9A for both inners, and the same for both outers).

Each bulb has an individual 17.5A rated cable to its fuse, (well within the 4.5A for an individual 60W halogen main), and the other side of the fuse to the switch, and the switch to battery feed is rated at 25.5A. Since the light switch does not allow dipped and main to be on at the same time, the lighting circuit will be drawing approximately 18A max, (four main beam halogen bulbs), so again well within the limit. The main beam flash is a separate switch, but again the max would be 18A.

The purpose of any fuse in a circuit is to protect the rest of the circuit from overload situations. Therefore the fuse MUST be the weakest link in a circuit. The cable, switches etc would always have a higher continuous current rating higher than the fuse, otherwise there is the risk of the other component failing first, (sometimes with disastrous results) :shock:

The main reason I, (and I'm guessing some others on this forum), added relays to my lighting circuits was to overcome the possibility of the so called 'fuse box meltdown' that has been known to take place, when the contacts of the fuse box do not make good contact. This is actually a prime example of a component in a circuit having a lower current carrying capacity than the fuse. The faulty fuse boxes can no longer take the current they were designed for, and the excess current is converted to heat, and they eventually melt and sometimes catch fire :(

As with any components on a 40+ year old car, the electric switches, connectors etc all need to be maintained to keep them at their best. Removing switches, cleaning them up and using switch cleaner on them, is just the same as removing a carb, stripping and cleaning it for example. Dirty contacts will always reduce the current carrying capability of a connection, and result in heat buildup :shock:

Sadly the electrics in a car don't always get the same maintenance attention they need, compared to the rest of the vehicle :shock: I read about us changing wheels/tyres, rebuilding engines/gearboxes, replacing brake/steering/suspension components, refurbishing interiors, but when was the last time you undid every single electrical connection, cleaned them and the switches, and put them all back?
 
codekiddie said:
in theory there should be no problem with the switches ability to take the extra current.
Click to expand...

I'm usually the first to argue that these components were more than adequate to handle the load when the cars were in regular use 30-40 years ago but I also suspect that the effects of age on these components has never really been analysed.

codekiddie said:
The main reason I, (and I'm guessing some others on this forum), added relays to my lighting circuits was to overcome the possibility of the so called 'fuse box meltdown'
Click to expand...

That may well be the case on S2 cars but on S1 cars the switches tend to take the lion's share of the load and do get very hot. In fact too hot to touch in the case of the sidelight switch. This switch carries all of the current for all of the headlamps when they are on. It's quite a scary experience to be driving along a dark road and have your headlamps suddenly go out :shock: No amount of cleaning and maintenance prevented it from happening again several months later, which is why I fitted a relay to bypass it. I suspected stress due to thermal expansion and contraction of the switch case and contacts was the prime cause of repeated failure on my car.

Dave
 
Dave3066 said:
I'm usually the first to argue that these components were more than adequate to handle the load when the cars were in regular use 30-40 years ago but I also suspect that the effects of age on these components has never really been analysed.
Dave
Click to expand...
Quite correct Dave. I would imagine that over the years the light switch contacts become pitted, with repeated on/off cycles etc... so that there is actually less surface area on the switch contacts actually touching, thereby reducing its current carrying capabilities. When fitting the relays, we are still using the same light switch that used to switch the high current bulbs. If pitting is an issue, the fact that a relay takes nowhere near as much current as the lights, explains why they will quite happily function.

Dave3066 said:
codekiddie said:
The main reason I, (and I'm guessing some others on this forum), added relays to my lighting circuits was to overcome the possibility of the so called 'fuse box meltdown'
Click to expand...
That may well be the case on S2 cars but on S1 cars the switches tend to take the lion's share of the load and do get very hot. In fact too hot to touch in the case of the sidelight switch. This switch carries all of the current for all of the headlamps when they are on. It's quite a scary experience to be driving along a dark road and have your headlamps suddenly go out :shock: No amount of cleaning and maintenance prevented it from happening again several months later, which is why I fitted a relay to bypass it. I suspected stress due to thermal expansion and contraction of the switch case and contacts was the prime cause of repeated failure on my car.
Dave
Click to expand...
Good point about the S1 cars not having the same issues with the fuse box. Living out in the country as I do with many unlit roads, I can only imagine how scary losing all lighting suddenly can be :(

Just something else I spotted....

codekiddie said:
Hi Jim

Whilst your figures are accurate, in theory there should be no problem with the switches ability to take the extra current.
Click to expand...
I was actually wrong to say this.

Your calculations were...

On main beam there is 50 x 2 plus 75 x 2 = 240W.

But the total is actually 250W and not 240W as stated. The Halogens on the other hand will be 60W x 4, which is only 240W so we are actually using less current :shock:
 
When you consider xenon lights give 80 lumens per watt and some manufactures are now fitting LED headlights giving 100 lumens per watt,
Click to expand...
Remember though that xenon lights are typically only 35 watt .I don't know about LED's but I would suspect it is even less
I'm in favour of halogens and I have those supposedly brighter bulbs that use the same current
 
DaveHerns said:
Remember though that xenon lights are typically only 35 watt .I don't know about LED's but I would suspect it is even less
I'm in favour of halogens and I have those supposedly brighter bulbs that use the same current
Click to expand...
Click to expand...

Hmmmm....
Incandescent = 2 x 37.5 x 16 = 1200 Lumens
Halogen = 2 x 50 x 30 = 3000 Lumens
LED = 2 x 35 x 100 = 7000 Lumens

No wonder modern lights are much better.

Of course this not all of the facts, Xenons are expensive to manufacture, LED,s need a limiting circuit but have a much greater life expectancy etc, etc..

All of this has little bearing on our favoured motors, except to be aware of the limits, and potential improvements of the ( beautiful ) twin headlights.
 
LEDS really are the way to go however they dont yet have the dip and high beam ability available to use on a retrofit system to fit older style headlamp shells unlike Xenon tech.
I would not ever consider going the xenon route with the p6 as high voltage tech is always inherently unreliable and it is likely to remain expensive and will in years to come become very difficult to upkeep as LED tech will dominate the market making old tech xenon inherently cost more due to its rarity and system complexity.

I sell Led torches and headlamps as a side line and can attest to there overwhelming superiority compared to halogen in brightness and the availability of different colour temperatures, even a small hand held torch with a single small lithium ion battery completely outshines a 100 watt Halogen spotlight let alone a full blown big torch with multiple batteries.

Graeme
 
Graeme
Do you have anything that sits on a rifle for whacking pesky possums and rootin rabbits .
Not too heavy and nothing that gets in the way of a scope .
Nice and bright narrow bream
Gerald
 
Nothing in stock at the moment unfortunately.
I have moved from my agricultural block recently and have been a bit involved in the transition to a non hunting / pest life style, no more possums and rabbits Yay :LOL:.
I found that you want about 900 to 1200 lumens to be very effective which is easily achieved in a small package either mounted above or below barrel.

Graeme
 
Geordie Jim said:
Hmmmm....
Incandescent = 2 x 37.5 x 16 = 1200 Lumens
Halogen = 2 x 50 x 30 = 3000 Lumens
LED = 2 x 35 x 100 = 7000 Lumens

No wonder modern lights are much better.
Click to expand...

But in many cases, too bright for purpose as has been previously discussed.
 
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