Technical I changed my stop lights with led but the warning light wont go away

[StanZlatan]

I changed my stop light with these lights led long life.

Pardon our interruption...

But the warning light has dissapeared yesterday now its back..

 

[StanZlatan]

So it appears when i press the stop pedal. Is the issue with the led lights?

 

[portland_bill]

Fiats seem to be more sensitive than other makes so despite claiming to be canbus compatible, your car may still not like them.

Firstly, ensure they're the right way around. Whilst they have offset pins, most bulb holders are flexible enough to allow them to be pushed in the wrong way, then you get the low wattage for brakes, and high wattage for marker lights.

If that's all Ok, check them with ALL lights on. All the bulbs share an earth connection. If the earth is poor, the current will try to find a path through other bulbs. A common effect is the brake lights earth through the marker filament, then through the wiring to the front of the car and earth at the front lamp. But if the marker lights are also on, the two currents cancel each other, both lights go out, and the warning illuminates.
Often you may see a car that signals a left or right turn, thenwhen they brake, the indicators and brake lights alternate, as they are fighting for an earth path.
Turn on marker lights, rear fog, reverse, hazards, then apply the brake.

 

[StanZlatan]

Yeah i borrowed two original and warning light dissapears. I was scammed!!!!!!!!!!

 

[StanZlatan]

I am returning them. Scammers everywhere

 

[the green vanper]

The resistance of the LEDs is different than those of tungstene wire bulbs. If you want to have LEDs, mesure the resistance of the original bulbs and find LEDs that has the same resistance. It is more likely it will work without issue.

 

[StanZlatan]

That seems like something the producer should do and pack ready. Resistance of led bulb is not stated either. Also i realised the original has two wires and switch between 5 and 21w. Led can never do that

 

[the green vanper]

Of course. But the majority are from cheap chinese factories where no one cares about it.

I have friends that have such LEDs in different cars and they work. And I know part of them bought them on aliexpress.

Just as a reminder, they are not street legal.

 

[Herts Hillhopper]

The correct LED bulbs, with both a 21w bright setting for brake lights and a dim 5w one for the night time lights (so, matching the specs of the original twin filament bulbs) will work, but you may have to add a resistor to the wiring. Most LED lighting has this clearly mentioned in the instructions. But why bother with LED? The standard bulbs are much cheaper and readily available from any car spares shop and actually, most supermarkets too. They last for years... and crucially also comply with the regulations too (they are 'E' marked... which LED bulbs are not)

Here's a good (ie reliable) Philips LED 21w/5w bulb: https://www.ledperf.co.uk/philips-p...led-bulbs-red-11499ru70x2-1157r-p-136655.html and for comparison, a standard filament one from Halfords https://www.halfords.com/motoring/bulbs/halfords-380-p21/5w-car-bulb-twin-pack-198243.html. The resistors that might be needed with the LEDs are here: https://www.ledperf.co.uk/philips-21w-resistors-for-p21w-p215w-w21w-w215w-led-bulbs-p-109932.html

 

[StanZlatan]

The correct LED bulbs, with both a 21w bright setting for brake lights and a dim 5w one for the night time lights (so, matching the specs of the original twin filament bulbs) will work, but you may have to add a resistor to the wiring. Most LED lighting has this clearly mentioned in the instructions. But why bother with LED? The standard bulbs are much cheaper and readily available from any car spares shop and actually, most supermarkets too. They last for years... and crucially also comply with the regulations too (they are 'E' marked... which LED bulbs are not)

Here's a good (ie reliable) Philips LED 21w/5w bulb: https://www.ledperf.co.uk/philips-p...led-bulbs-red-11499ru70x2-1157r-p-136655.html and for comparison, a standard filament one from Halfords https://www.halfords.com/motoring/bulbs/halfords-380-p21/5w-car-bulb-twin-pack-198243.html. The resistors that might be needed with the LEDs are here: https://www.ledperf.co.uk/philips-21w-resistors-for-p21w-p215w-w21w-w215w-led-bulbs-p-109932.html

Thanks but none of these work for me more then 6 months. Ones i do use are ultralife Osram and they last most 2 years

 

[the green vanper]

I don't assume so many of the bulbs are bad.

Are you sure the wires are OK? The holders, bases, how do you call them in English? Perhaps there a bad contact somewhere and it makes the bulb to blink constantly?

From my experience the Tungsram bulbs are the best, but I know they closed the European factory 2 or 3 years ago So probably won't be the same with the new ones, coming probably somewhere from Asia.

 

[StanZlatan]

I don't assume so many of the bulbs are bad.

Are you sure the wires are OK? The holders, bases, how do you call them in English? Perhaps there a bad contact somewhere and it makes the bulb to blink constantly?

From my experience the Tungsram bulbs are the best, but I know they closed the European factory 2 or 3 years ago So probably won't be the same with the new ones, coming probably somewhere from Asia.

The only way i know how to tell if the metal pieces contacting the bulb is if they are black burnt. I had such case at the front and had to buy entire lamp as even morgues sold it all in complect.
My bulb holders look fine. I talked with some delivery drivers of peugeot 107 , clio and so on and thats similar answer. Good bulbs last about a year

 

[the green vanper]

Oxidation can be seen with you own eyes, too. Same for proper contact between the bulb and the holder, but you have to look from the bottom.

 

[StanZlatan]

Right side in rear burns may be 50 persent more. I am not specialist to tell if connection is good or not. I raised question of rust and moisture on right side and my mechanic said its because i ait on right side and water drains on that side. So that would mean most drivers in uk would have similar issue

 

[Herts Hillhopper]

Right side in rear burns may be 50 persent more. I am not specialist to tell if connection is good or not. I raised question of rust and moisture on right side and my mechanic said its because i ait on right side and water drains on that side. So that would mean most drivers in uk would have similar issue

A bulb should not fail more if the connection is bad -- in fact that would make it less likely to fail as it would be getting less current through the filament (the wire inside the bulb). Corrosion shows up as a white deposit (like a salt water stain), usually on the metal 'can' part of the bulb holder that the bulb fits into, or on the metal part of the bulb itself. It is very easy to see, as if not corroded everything is clean and shiny silver. The other possibility is that the two metal pins in the holder that touch the bottom of the bulb are sticking down -- they should move in and out if you push them with the end of a small screwdriver (be sure the brakes are not being pressed at the time!) because there is a spring underneath them. If they are sticking, then the contact is less good and you can see some blackening (which is not good). Usually they become free if you push them in and out a few times. A small amount contact clearer or WD40 will free them up if they are stuck.

Also, as I am sure you have already spotted, the bulbs will only fit one way round - the small pins sticking out of each side of the bulb are at different heights. If you really push hard enough it will go in 'the wrong way round' too -- but this means the wrong filament of the bulb is being used. The right way round they will fit in very easily indeed.

 

[the green vanper]

the bulbs will only fit one way round

The problem is there are three types of the socket for the 5/21W bulbs and frequently people do not know it and just buy the first / cheapest one, which can, but don't have to be the correct one (an image from one of my previous posts):

 

[Herts Hillhopper]

The problem is there are three types of the socket for the 5/21W bulbs and frequently people do not know it and just buy the first / cheapest one, which can, but don't have to be the correct one (an image from one of my previous posts):

View attachment 460236

It is (here at least) very hard to buy anything other than the correct one (the middle one in your picture)... unless you go online and search with specialist classic car supplier rather than to a shop

The other types are used in older, or non EU/UK spec cars so actually pretty hard to find. Halfords, Screwfix or Amazon (as examples) all list the correct sort...

https://www.halfords.com/motoring/bulbs/halfords-380-p21%2F5w-car-bulb-twin-pack-198243.html

https://www.screwfix.com/p/osram-bay15d-auxiliary-on-road-bulbs-aux-p21-5w-21-5w-2-pack/602KL

https://www.amazon.co.uk/380-12v-Car-Bulb-x10/dp/B002BFLX8A

 

[the green vanper]

The BAU15D was apparently used by Mercedes, BMW, Volkswagen. Don't know the years however. There was another, older standard, which is BAW15D. And was very similar to BAU15D.

I can't discuss what's available in shops in the UK I know both BAY15D and BAU15D are available in specialized automotive shops in Poland. And I assume also here the BAY15D is more popular now.

I'm pretty sure I've seen it on some vehicle lately, but none of the dailies nor the Ducato don't use them. So, there's still my motorbike and the scooter (which both are a couple of years older). Or could be my father's of friend's French 'inventions'.

Nevemind, the idea was to show that there are different base bulbs and this also could be a cause of the light not working.

 

[portland_bill]

Whilst theory says that a poor connection should not cause a bulb to fail prematurely, it does in practice. Bulb needs to be snug in its holder, to give a good earth path, and the connectors need to bear on the contacts with enough pressure to maintain a good connection as they heat up.

Is it the brake (21w) filament that fails? A common reason for this is the habit of holding on the brake pedal when stopped at junctions. that keeps the light on, making them run hot for longer than ideal. A better procedure is to use the handbrake when stopped, and release the brake pedal. Indicator bulbs, although also 21w, last a very long time because they don;t get hot, being switched off before they reach full temp, then on, off, etc.

 

[JayAre]

Is it the brake (21w) filament that fails? A common reason for this is the habit of holding on the brake pedal when stopped at junctions. that keeps the light on, making them run hot for longer than ideal. A better procedure is to use the handbrake when stopped, and release the brake pedal. Indicator bulbs, although also 21w, last a very long time because they don;t get hot, being switched off before they reach full temp, then on, off, etc.

which is exactly what many members here (and elsewhere) advocate in order to use the ‘hillhold’ feature