Car blinker system (US)

[aurmer]

I had to replace my tail light blinkered socket because even a new bulb didn't work. Unfortunately, after installing the new socket, the light works great, but the system itself is still blinking twice as fast, as to indicate a mal functioning light.

Google only told me time and again "your light is out", but I am asking, what does the system use to determine whether or not the light is out? Current sensor? Other?

Thanks for any advice.

[cowana]

Usually a current sensor.

Some of the LED replacement bulbs you can buy market themselves as 'CAN Bus compatible', meaning they have a load resistor meaning they draw a similar current to a regular incandescent bulb.

[Adam60]

Younever said what year, make and model the vehicle was so hard to give you a good answer. If we know what generation of flasher you have, answer will be pretty accurate. If you are blinking fast on one side, you still have a problem. Measure the voltage at the socket for the ground side of the circuit when it is flashing. There should be no voltage. If there is, you have a bad ground. Measure thevoltage input on both sides and use an average if you can. Is there much of a difference? Is the new socket you put in soldered connections or crimped. If crimped, make sure connections are good.

[Brumby]

My guess is you've used an LED 'globe' on a system that uses a current driven flasher can - the less current drawn, the faster the flashing.  This is an intentional design feature - for the sole purpose of letting the driver know there is a problem.

Assuming all lights are working, the lower current draw from an LED 'globe' will cause the symptoms you are describing.

[NottheDan]

Are the LED kits road-legal over there?

[CatalinaWOW]

You didn't state the age of the car, but older cars used a thermoelectric flasher system.  The light current was passed through a heater wire wrapped around a bimetal strip, which opened the contact as the bimetal strip heated.  It then cooled and closed the contact.

In these systems a heavier load would cause the light to flash faster.  In fact the extra load of paralleling in a set of trailer lights triggered this behavior.  And created a market for heavy duty flasher modules which flashed at an appropriate rate when attached to a trailer, but flashed slowly and deliberately when the trailer was not in use.

Due to the conservative nature of the auto industry, I suspect that this behavior has been emulated in newer electronic versions.   A fast flash would normally indicate higher current, possibly from a possible partial short to ground.

[Brumby]

In Australia we see faster flash rates when a globe has failed - ie, a reduced load.

[Cliff Matthews]

Basic enough to roll your own..

http://www.instructables.com/id/Simple-Motor-Bike-indicater-Flasher-unit-in-a-TIC-/

[Brumby]

Also in Australia is the requirement that the flasher system makes an audible indication.  The old thermal contact can makes a clicking sound, so that the driver doesn't need to look at anything to know the flashers are operating.  A silent electronic solution would not comply.

[Zero999]

Are the LED kits road-legal over there?

I don't see why not, as long as they comply with the relevant regulations. If the flash rate is too fast/slow, then it won't be legal but otherwise it should be fine.

About 5 years ago I had an accident on my motorcycle and damaged one of the indicators. The lamp holder was broken, even though the rest of the assembly was fine, so I removed it and replaced it with some orange LEDs and a suitable series resistor and glued it back together. The indicator worked fine but flashed too quickly so it failed the MOT as a result. I added a suitable resistor in parallel with the LED indicator, so it flashed at the correct rate, sent it in for the MOT and it passed.

[Seekonk]

Basic enough to roll your own..

http://www.instructables.com/id/Simple-Motor-Bike-indicater-Flasher-unit-in-a-TIC-/

That circuit likely won't work with a LED unless some resistor is placed across the LED.  It wouldn't have to pull a lot of current, just enough to let the capacitor charge to a higher voltage.  The LED would act like a zener and there wouldn't be enough gate voltage for the FET.  If battery voltage was high enough and the FET had a low gate voltage it could work, but I wouldn't want to be stuck on the side of the road hoping for the best.

[rbm]

Also in Australia is the requirement that the flasher system makes an audible indication.  The old thermal contact can makes a clicking sound, so that the driver doesn't need to look at anything to know the flashers are operating.  A silent electronic solution would not comply.

Ha, like audible feedback is going to alert the driver to an operating flasher that needs to be cancelled.  Not likely to work in North America what with all the distracted drivers.  I can't tell you how many time I see people driving along for kilometers with their flasher going and not making any lane change or any exit in the vicinity.

[Brumby]

Don't worry, I've seen that here in Australia - but without audible feedback you would see it a lot more.

[CatalinaWOW]

The problem is that a lot of the sound energy from the clickers is at higher frequencies, where hearing loss gets more common with age.  At my age I can barely hear the audible part when driving at low speed, not at all at highway speeds.

Classic case of not taking all human factors into account.  It is further accentuated in my case since from my sitting position I can't normally see the visual indicators either.  That is one reason some car manufacturers have made the front signal visible from the drivers position.

[NottheDan]

Classic case of not taking all human factors into account.  It is further accentuated in my case since from my sitting position I can't normally see the visual indicators either. 

How does that work? They are usually in the centre of the dashboard and if you can't see the dashboard something's wrong with your sitting position.

[Brumby]

I've noticed in some vehicles they are slightly recessed which will restrict the viewing angle.

Remember, a lot of ergonomic decisions are derived from an 'average' person - and there are some people less average than others.

[Cliff Matthews]

Classic case of not taking all human factors into account.  It is further accentuated in my case since from my sitting position I can't normally see the visual indicators either. 

How does that work? They are usually in the centre of the dashboard and if you can't see the dashboard something's wrong with your sitting position.

Centre of the dash? Maybe yes, in a Mini or in the old dart, but cars from NA and Japan put most everything but the climate controls in one big molded plastic "pod" just behind the steering wheel. Maybe it's so the dealers can charge us more for repair..
With so much tech advancement elsewhere, one would think ergonomics could get some priority, but maybe radical ergonomics would cause accidents. The HUD seems like a great idea for the Corvette, so why didn't they expand that? Could it be that Insurance Companies might charge buyers higher premiums on big changes?

[Cliff Matthews]

I owned a 2000 Dodge Caravan and it had all the idiot lights up on top. It was rare to leave the turn signal on (confusing other drivers).
This is one thing I wish my 2008 Caravan had.. and they call that progress?

[Zero999]

Also in Australia is the requirement that the flasher system makes an audible indication.  The old thermal contact can makes a clicking sound, so that the driver doesn't need to look at anything to know the flashers are operating.  A silent electronic solution would not comply.

Simple. On modern cars, with an electronic flasher, a small speaker is used to generate the click noise. It shouldn't be difficult to add a speaker to your own design.

[NottheDan]

Classic case of not taking all human factors into account.  It is further accentuated in my case since from my sitting position I can't normally see the visual indicators either. 

How does that work? They are usually in the centre of the dashboard and if you can't see the dashboard something's wrong with your sitting position.

Centre of the dash? Maybe yes, in a Mini or in the old dart, but cars from NA and Japan put most everything but the climate controls in one big molded plastic "pod" just behind the steering wheel. Maybe it's so the dealers can charge us more for repair..

That is the dashboard. The part that faces the driver. I'm not talking about those cars who have their instrument pods above the centre console but with the instrument panel behind the wheel. If you can't that then you have chosen a wrong seating position or a really really unsuitable car. So for someone to go "Oh, I never see that." ... That's somewhat worrisome.

[SeanB]

Shoot, here using indicators would be a luxury, most vehicles rarely have working lights at all, you often see a vehicle driving at night with the only working light being one headlamp, possibly even aimed at the road.

I did call the RTI one evening to report a HGV driving without any lights at all, aside from some very dim working emergency lights. They pulled him over, fined for the non working lights, and also found the vehicle was otherwise not roadworthy and overloaded. Helps to have the direct number for the control room, and they tend to want to keep these moving wrecks off the road, so they do not have to clean up the aftermath.

As to panel design, often the function is overruled by appearance, so you might have lamps that are obscured by the steering wheel at times, or are not easily visible, or are just plain too small, to fit in the style. Like using a 2mm diameter red LED as an engine temperature warning light, and a 15mm blue LED as a bright beam indicator, right next to each other. Then run the red LED at glowworm level, and the blue at laser light level.  Gauges that are tiny, and obscured by most driving positions. Then add a display that tells you all sorts of things, like the fuel range, transmission settings, mirror positions, seat positions, but that does not tell you coolant level is low when driving, or that the engine is approaching nuclear meltdown because the radiator hose ( which was recalled 6 months before, but the dealership did not do, despite having the vehicle in at least a dozen times in the interim, and having the hoses in stock for this) was known to break at the engine side.

[Delta]

I owned a 2000 Dodge Caravan and it had all the idiot lights up on top. It was rare to leave the turn signal on (confusing other drivers).
This is one thing I wish my 2008 Caravan had.. and they call that progress?

What kind of maniac takes a photo whilst driving at nearly 70MPH, with the poor engine massively overheated, with low oil pressure, screaming at 5000RPM! 

 

[Zero999]

Basic enough to roll your own..

http://www.instructables.com/id/Simple-Motor-Bike-indicater-Flasher-unit-in-a-TIC-/

That circuit likely won't work with a LED unless some resistor is placed across the LED.  It wouldn't have to pull a lot of current, just enough to let the capacitor charge to a higher voltage.  The LED would act like a zener and there wouldn't be enough gate voltage for the FET.  If battery voltage was high enough and the FET had a low gate voltage it could work, but I wouldn't want to be stuck on the side of the road hoping for the best.

Simulating it in LTSpice seems to suggest it will work with LEDs. One thing which will make it better at lower voltages is to use a logic level MOSFET, which will have a low enough threshold to turn on, but it would be advisable to protect the gate with a 15V transient suppressor diode.

[Delta]

I had to replace my tail light blinkered socket because even a new bulb didn't work. Unfortunately, after installing the new socket, the light works great, but the system itself is still blinking twice as fast, as to indicate a mal functioning light.

Google only told me time and again "your light is out", but I am asking, what does the system use to determine whether or not the light is out? Current sensor? Other?

Thanks for any advice.

Just use a proper incandescent bulb, instead of some daft LED thing...

[Cliff Matthews]

I owned a 2000 Dodge Caravan and it had all the idiot lights up on top. It was rare to leave the turn signal on (confusing other drivers).
This is one thing I wish my 2008 Caravan had.. and they call that progress?

What kind of maniac takes a photo whilst driving at nearly 70MPH, with the poor engine massively overheated, with low oil pressure, screaming at 5000RPM! 

 

Ha! not my pic but funny. Now I recall each time it started, it did some kind of impressive self-check with all the needles cranked.