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Headlights Hi-Lo

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Rick60

Rick60

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I'm in the progress of installing auxiliary Lucas drive lights to my BT7. While planning the electrics I recognized that, when the headlights high beam is switched on, the low beam is switched off. The diagram in the manual makes it clear, why this happens. The footswitch works only in one "direction".

Does anybody know, why this was done in this way? On modern cars the low beam stays on when you switch to high beam.

I'm asking this, because I want to implement a circuit which allows me to flash the headlights.

The only reason I can imagine is possible overload of the wires and/or lights with both on.

Tks.
 
Rick,
I added to Lucas aux. fog lights to my BJ8. I found two web sites that were helpful. www.danielsternlighting.com/tech/relays/relays.html and www.team.net/sol/tech/light-up.html
One thing I did learn is that the wiring for Austin Healeys and all LBC's is not very heavy, generally only 18 gauge wire goes to the headlamps. That's the equivilent of speaker wire. I imagine if the low beams stayed on with the high beams, there would be some burning wires somewhere.
When I hooked up my aux. lights, I used a relay to turn them on and ran new 14 guage wire from the relay to the fog lamps. I have a BJ8; so to turn the fog lamps on, I replaced the panel light switch with a second head lamp switch. The first position on the new head lamp switch turns on the panel (dash) lights. The second position turns on the fog lights, by applying power to the relay. Panel lights stay on as well in position 2. Please note that this new switch and the old panel light switch gets power from the original headlamp switch, which must be on in position 1 or 2 (side/tail or headlamps)for it to work. This turned out to be a clean looking installation without the need to drill a hole in the dash for another switch.
 
My 1960 BT7 also has Lucas fog (actually driving) lamps. When I installed them I was concerened with circuit overload issues also, and considered a relay and separate wire arrangement. But before resorting to that, I figured I would try something else first.

Since I was rewiring the car with a new harness, and making all the wire-to-terminal connections with solder and all the slip-on connections with electrolytic grease, the system should be performing well, and possibly be able to carry additional load.

So I did two things. The driving lamps got wired directly to the high beam circuit right at the front of the car. And the whole light circuit got its own fuse way back at the dash switch. I forget the fuse size, but it was intentially small enough to protect the gauge of the wire. I figured if the load blew the fuse, well, I might have to run another wire to the driving lamps etc like Shorn has done. However, since I was installing a nice neat harness, I did not want to bugger up the looks with additional wires strung here and there. But, somewhat to my surprise, it all works fine as I built it. I guess the new harness was assembled with heavy enough wire for this sort of additional load.

And yes, the low beams go off as the high beams go on. That is the convention of the older big bulb twin dual mode headlights insofar as I can recall. You can try wiring it differently at the foot switch, but I don't think the bulbs are made to take the heat of both circuits being on at the same time.

All this is just my two cents. Hit delete if not entertained or informed.

All the best.
 
HI Shorn, Hopefully you picked up the switched power source for the relay at the Starter terminal. /ubbthreads/images/graemlins/thumbsup.gif---Keoke /ubbthreads/images/graemlins/thumbsup.gifShorn
 
/ubbthreads/images/graemlins/savewave.gif
HI Brian, Does your wiring method mean that you can only have Driving lights on when you select HI Beam??---Keoke
 
Hello all,
not having a modern car I can't comment on current (sorry for the pun) practice. However I cannot think of a reason for having both main and dip filaments on simultaneously. It will not give improved vision.
Driving lamps, which I take to be long range lamps, will dazzle oncoming traffic so it is logical to have them switch off when switching to dip beam.

Alec
 
Piman, I guess if you have Main and Dip filaments on simultaneusly, the Dip filament certainly will not contribute to dazzeling the on coming traffic and may be just an economical way to mechanize things. Late model Daimlers do it that way,---Cheers Keoke /ubbthreads/images/graemlins/smile.gif
 
Keoke asked: "Driving lights on when you select HI Beam?"

Yep. I combined the adjustment of the high beams and driving lights to provide the best pattern working together. This combined pattern works quite well. I get a lot more side coverage for cornering than the high beams alone afford.
 
Brian,

I notice you have them on a light bar. Do they bounce? I have hear tell of mounting these on "L" brackets attached to the bumper brace with the mount hole through the front splash shield.

Tracy

Congrats on San Juan Batista by the way!!
 
OK Brian, I agree on the benefits, However. it is CA Illegal; /ubbthreads/images/graemlins/grin.gif also in the event of a HI beam failure so goes the driving lights.Using the technique Shorn chose and a similar' form I also use we can choose and select the light combinations required, both sets of lights are independant and no additional Hi current circuits are carried inside the cockpit area.This is not intended as criticism just a comparison of the two methods.-FWIW---Keoke
 
Thanks to all who responded and gave their opinions. The link to the Daniel Stern lighting site was very helpful.

Keoke: This pattern is the only legal pattern in Europe, at least in Germany. Auxiliary lights, as long as they are no fog lights, may only go on with high beam.

Piman: The advantage of having both, high and low beam, on is a much better illumination for the first 30ft in front of your car when driving with high beam. I think it's common practice with nowadays cars.

With your suggestions and some more research on the web I came to the conclusion to ban high current from the cockpit and control the lights via relays.

For those of you who are interested in the electrical layout a diagram is attached. In case it's not clearly visible give me a note and I'll send it to you.

Reviews and proposals for perfectioning are always welcome.

Regards
 

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Bighly, we did not mean to ignore your question "Do They Bounce"? Of course they bounce ,but tying them to the bumper brackets does not stop them from bouncing cause the bumper bounces too!-Keoke /ubbthreads/images/graemlins/laugh.gif
 
Keoke,

As I suspected. The badge / light bar is less intrusive and not much different in "bounce".

Cheers!!

Tracy
 
Hello Keoke,
I do not understand your point, of course the dip beam won't dazzle, but the main beam will. I also still maintain there is no benefit either from the driving seat or the engineering aspect.

Alec
 
Piman, operationally; switching from the Dip position to Hi beam or the other way around only requires switching the Hi beam lamps.Both lamps on as has been indicated by others improves visibility in close proximity to the car.Additionally, this design allows easy implementation of flashing when in dip mode or the lights are off. I can't comment on the engineering aspect as I did not design it-FWIW---Keoke
 
/ubbthreads/images/graemlins/savewave.gifBighly;

I wish I had said that. "Less Intrusive". Thats a good one on you---Keoke /ubbthreads/images/graemlins/thumbsup.gif
 
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