I presume cars are made a economically as possible, so is it really the case that a rear light unit with LEDs and driven by CAN bus, with two thin wires for the power and two even thinner wires for CAN-H and CAN-L bus is really cheaper to make than one with convention bulbs and much thicker wires?
The modern system does not make connecting a trailer light socket easy!
Well yes, because thick copper is expensive, and those 4 wires (and multiple CAN chips) can individually drive tail/brake/indicator/reverse/fog lamps ...
Also the chips start to do snazzy things such as dimming one side's front running lamps when indicating or providing the "moving pulse" on newer indicators
Actually, it makes it easier and it can be more clever. One thick wire as the main supply, then thin wires can be used to pick up the signals. The trailer lights can be monitored and issues fed as data down the can-bus.
what's so new about this? I was at an international exhibition in Hamburg in the '70s. There was a Leyland bus that was wired in this way. 40 years ago!
To hi-jack this thread slightly, it seems to me that the indicators on many modern cars are significantly less visible, especially off-axis, than those of older vehicles. Being positioned very close to bright LED running lights does not help in other cases, too (so dimming these seems an excellent idea to me).
Yes. And then you plug in a trailer with LED lights and the damned monitoring pulse causes the lights to visibly flash every few seconds. I had to change the trailer back to filament lamps thus losing the reliability benefit - grrrr!
VW Golfs of recent vintage are terrible for visibility of indicators: the front ones are placed close to the headlights and the back ones are right next to the brake lights. Gone are the days when you had a side light / indicator cluster that was totally separate from the headlights - maybe within or underneath the bumpers.
I'm surprised that various countries haven't collectively mandated more stringent Construction and Use regulations which require the indicator to be as far as possible from any other source of bright light (headlight/DRL at front, brake/fog at rear), and returning to the old days of function being more important than style.
I too think that modern cars' indicators are far less conspicuous, especially in daylight when the light reflected off the clear "glass" of the cluster makes it harder to see the slightly brighter "on" phase of the flashing light.
Well it no doubt depends on the vehicle, but the manufacturer can make the car without any cable thick enough to power trailer lights, running to the back of the vehicle.
I must admit that I am fed up of seeing vehicles that appear to be about to pull out from a row, only to find as I get there that they have hazard lights on.
Seems to be. When you make electronics in bulk they may well be cheaper to the factory than high current cables and switchgear. But not, of course, when it comes to buying replacements, if needed.
So saying, my last car was an early adopter of this idea, and the electrics were very reliable even at getting on for 20 years old.
I spotted a car the other day that turned off the running lights on that side while the indicator was flashing. It certainly worked to make the indicator more visible.
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