850 AC blue LED replacement

I took my '95 850 in to have the burned out lights in the climate
control replaced. The entire unit was black except the small yellow LED
for the recirculate switch. The dealer replaced the light bulbs, but
claims the blue LED for the AC switch is part of a $200 switch module.
Is there some way to replace the blue LED?

 

Can you take it apart and resolder a new one in? Those blue LEDs are the
most expensive ones, but they are only a few bucks (as opposed to less then
one dollar for something like a red one)... The thing is tho, I have doubts
that it burnt out, LEDs have a lifespan of over 20 years! - something burnt
it out (too much current) or the connection has gone bad... so it might be
nessessary to buy the module... tho at $200 for a switch module I would live
with out it.

 

Ouch!

LED's almost never burn out unless abused by a bad design, they should last
around 100k hours which is far longer than your car will last. Perhaps it's
actually an incandescent lamp? Often they're burried in switches and not
meant to be replaced, however it's not particularly difficult to get most of
them apart and they can be replaced with an LED and resistor.

 

Blue LEDs were not on the market yet in 1995. They were invented in about
1998 and mad eit to the market (in record time) by about 2000. It must be a
bulb with a blue cover.

 

On my old 1991 Golf, it used LED's to display what was going on, a green one
to indicate turn signal activity, a red for coolant temp, oil pressure, and
generator failure, and a blue one for its highbeams are on lamp (and yellow
for the glow plug/water separator lamp on diesels).... It was pretty dim,
I've seen much brigher ones in my friends two Jetta's (a 1990, and a
1991)... Sure as hell looked like a blue LED tho.... Maybe super bright blue
LEDs haven't been on the market since 1998-2000 but the low intensity ones
seem to have been... all you really need for a switch, or a function
indicator lamp.

BTW, yes I am aware that blue is a more difficult colour of LED to make, and
that even in super bright format the blue ones are still quite a bit less
bright then the other colours.

Maybe Volvo used a similar low intensity LED lamp for its climate control
switch.

 

That explains why the yellow one is still working and the blue one
isn't. The yellow one is probably an LED.

 

Robert: I would agree that the light in the Climate Control is not an LED,
but they got to market a little sooner than 2000. I tinker around with some
of these and make some lights for my Grandkids to play with. ( they think
its pretty cool & its a good mental excersize for me.) I offer the
following for your perusal.

Commercially viable blue LEDs based on the wide bandgap semiconductor
gallium nitride were invented by Shuji Nakamura while working in Japan at
Nichia Corporation in 1993 and became widely available in the late 1990s.
They can be added to existing red and green LEDs to produce white light.
Most "white" LEDs in production today use a 450nm - 470nm blue GaN (gallium
nitride) LED covered by a yellowish phosphor coating usually made of cerium
doped yttrium aluminium garnet (YAG:Ce) crystals which have been powdered
and bound in a type of viscous adhesive. The LED chip emits blue light, part
of which is converted to yellow by the YAG:Ce. The single crystal form of
YAG:Ce is actually considered a scintillator rather than a phosphor. Since
yellow light stimulates the red and green receptors of the eye, the
resulting mix of blue and yellow light gives the appearance of white.

White LEDs can also be made by coating near ultraviolet (NUV) emitting LEDs
with a mixture of high efficiency europium based red and blue emitting
phosphors plus green emitting copper and aluminium doped zinc sulfide
(ZnS:Cu,Al). This is a method analogous to the way fluorescent lights work.

The newest method used to produce white light LEDs uses no phosphors at all
and is based on homoepitaxially grown zinc selenide (ZnSe) on a ZnSe
substrate which simultaneously emits blue light from its active region and
yellow light from the substrate.

Harold

 

So if the Blue LED was invented in 1993 as you say- what colour was that
blue "LED" in my VW of 1991 vintage?.... White LED with a Blue housing? -
the casing was a translucent Blue plastic.

 

If it had a blue housing it was not a true blue LED as the housing on a
true led is water clear.


Harold

 

There were no white LEDs until the blue LED was invented. What they did
to make white was to use a white phosphor on an LED but the quality was
poor and the life was substandard. The VW probably used colored
miniature tungsten lamps similar to the ones in MagLites.

 

Looked the same as the genuine LEDs parked next to it at least... Tho it was
really dim (didn't know if the high beams were on during the day it was so
bad - then again, never switched the lights on during the day as it had
front and rear running lights - so the beams, even if pulled on, wouldn't
stay on).

Thanks for the"enlightening" information.

 

I have a similar problem. I can still see the AC light but mine appears
rather violet and very, very dim. It's impossible to see in daylight.

The light wouldn't bother me if the AC still worked.

 

Sure they have been, bright blue LED's matured around '95, dimmer ones were
around several years prior to that. I remember though at one point they were
something like $40 each.

 

White LED's are blue LED's with a phosphor to emit white light. Blue LED's
are usually water clear when off, but I do have one that's milky blue
diffused.

 

Blue?? LED
There are no blue led´s in the panel......or ?

XR(V)

 

My '95 850 without automatic climate control had a blue indicator lamp
to tell when the AC was on. It doesn't function any more. The Volvo
garage called it an LED and said it was part of the switch module. The
panel has since informed me that blue LED's were in their infancy in '95
and probably not in Volvos. However, it still had a blue lamp of some
kind.

 

It's probably a blue incandescent lamp, if you can find a used switch in a
junkyard I can replace the lamp for you, or retrofit it with an LED if
desired.

 

It might also be a white light under a blue plastic filter.

 

Well that's a given, all incandescent lamps are "white" under whatever
filter, whether it's painted on or slipped over the bulb.