LEDs

[GCS_XLR]

Recently I replaced the bulbs in the map lights on the rear view mirror with LEDs, much nicer than the originals.
The only issue is the LEDs never completely shut off, there is always a soft glow. Power draw has to be very small
and no problems yet with a low battery.
Has anyone else experienced this problem?

 

[Phrede]

Recently I replaced the bulbs in the map lights on the rear view mirror with LEDs, much nicer than the originals.
The only issue is the LEDs never completely shut off, there is always a soft glow. Power draw has to be very small
and no problems yet with a low battery.
Has anyone else experienced this problem?

I've not experience that exact problem but many times a load resistor is required on LED conversions. Since the control circuit is a sinking type I suspect that may be the case here.

 

[GCS_XLR]

I've not experience that exact problem but many times a load resistor is required on LED conversions. Since the control circuit is a sinking type I suspect that may be the case here.

Thanks for the fast response, I'll check that out.

 

[PAK XLR8]

Interior LED's

Thanks for the fast response, I'll check that out.

The interior lights are scheduled to "fade" after you shut the door. The way the system is set up, they don't give power when you open the door and then fade them out gradually - they have 12 V to both sides of the bulb and drop one side to zero when you open the door - slowly bringing the voltage back up on the backside to 12 V when they "fade". In the regular bulbs, this reults in no lights when both sides are "hot", and lights up when the computer drops the voltage on the backside and slowly raises the voltage later.

In the case where you still see some dim light well after the doors have been closed, this is simply a matter of the voltage not coming completely back to 12V on both sides - there is a slight differential voltage to make the LED's active. I learned all of this with a volt meter, when I was trying to get my LED's on my Windrestrictor hooked up to my courtesy lights (with a diode to isolate). My Windrestrictor would not operate with the courtesy lights, so I had to install a relay - which does not like the fade part of the courtesy lights.

Long answer to a short question - but that is how these lights operate and the LED's will still stay "on", if they have more than 0.7 V of differential in the proper direction (small light - 12 V for full light). This is why they tell you to install them in one way only - they won't work in the opposite direction. Hope this helps...

 

[Phrede]

The interior lights are scheduled to "fade" after you shut the door. The way the system is set up, they don't give power when you open the door and then fade them out gradually - they have 12 V to both sides of the bulb and drop one side to zero when you open the door - slowly bringing the voltage back up on the backside to 12 V when they "fade". In the regular bulbs, this reults in no lights when both sides are "hot", and lights up when the computer drops the voltage on the backside and slowly raises the voltage later.

In the case where you still see some dim light well after the doors have been closed, this is simply a matter of the voltage not coming completely back to 12V on both sides - there is a slight differential voltage to make the LED's active. I learned all of this with a volt meter, when I was trying to get my LED's on my Windrestrictor hooked up to my courtesy lights (with a diode to isolate). My Windrestrictor would not operate with the courtesy lights, so I had to install a relay - which does not like the fade part of the courtesy lights.

Long answer to a short question - but that is how these lights operate and the LED's will still stay "on", if they have more than 0.7 V of differential in the proper direction (small light - 12 V for full light). This is why they tell you to install them in one way only - they won't work in the opposite direction. Hope this helps...

AKA a sinking output from the control. The fading is done by variable PWM of the output. I could go into output design, ie. open emitter v open collector, etc. etc but still maintain a load resistor to emulate the low cold resistance of an incandescent bulb will work.

 

[onalaska]

I have replaced my rear view mirror map lights with LEDs and have not noticed this problem. They cut off completely. I also have them in the doors and in the footwells and they all shut off normally. They just do not fade down to off like the incandescent bulbs did. Maybe it's the difference in the brand or type of LED? I actually used LEDs from two different suppliers and they both work normally.

 

[GCS_XLR]

To all that responded to my issue: LEDs not shutting off completely.
Thank you for your time and thoughts on this matter.
GCS_XLR