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2018 Subaru Forester XT CVT
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Discussion Starter #1
I was told there is a TSB pertaining to LEDs causing wiring and heat problems when replacing fog lights. I would like to see that TSB, mainly because LEDs generally run cooler. I did search the forums, and I see lots of opinions on why I should not do this, but what I want is not opinion, I'd like to see that Service Bulletin. Can anyway point me to it?
 

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1999 Forester S
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457 Posts
Are you talking about installing aftermarket plug 'n' play LEDs installed in the stock fog lamp housings?

If yes, be aware that OEM and aftermarket LEDs are not created equally. OEM LED assemblies often have active cooling modules with heat sinks that often dwarf the actual LED assemblies themselves.

Aftermarket LEDs often use passive cooling. A few aluminum fins, maybe a large ground strap soldered to the bulb as a "heat sink". Some even have fans, but realistically, they're still going to fail in short order because the fans aren't sufficient to cool the assembly, while also having poor construction.
 

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2018 2.0 FXT-Touring CVT
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2,934 Posts
One of my OEM foglights just died. So, no LED's for me... I guess.
 

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2010 Forester 5-speed manual
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169 Posts
Go to the Subaru website and then go to the Owners pull down menu. Follow to the Recall icon and submit your VIN. Any applicable recalls should come up. As for the TSB, as with Service and other manuals find the link on the same website to purchase a $35.00 license for 24 hours to download any and all TSBs that are available for your VIN, plus any other documents and information you find applicable.

LED lamps for automotive applications run very hot for driving light applications that I have seen. Passive heat sinks and /or cooling fans are needed. This means much of the energy needed to "drive them" is converted to large amounts of waste heat.

I have found that though American lighting laws are restrictive as compared to Europe, US market spec halogens lamps are the most cost effective in terms of performance, light output, and longevity. The High-intensity discharge lamps work great. I have them on my wife's MINI and they were on my former VW Touareg. They are great lamps and self adjust, but they are complex light assemblies and bulb replacement, when and if needed, is measured in the hundreds of dollars.
 

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2018 Forester XT Limited CVT
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651 Posts
LED lamps for automotive applications run very hot for driving light applications that I have seen. Passive heat sinks and /or cooling fans are needed. This means much of the energy needed to "drive them" is converted to large amounts of waste heat.
The LEDs will have a forward voltage (voltage across the LED) and a current through them, and part of their dissipation is heat. Unlike an incandescent filament, which is a thermal device that radiates the heat right out of the device itself, and that operates at very high temperatures, the heat from the operation of the LED is channelled away through heat sinks and then transferred to the ambient environment. That's why you will find heatsinks attached to LED elements, but not incandescent elements. The rate of heat transfer from the heatsink to the surrounding air is proportional to the surface contact area between the heatsink and the air. You can also use a fan to move air past the heatsink but I don't like fans because that's just another thing to break down/wear out. To increase the amount of surface-area contact, manufacturers will add lots of fins, and the fins themselves may also be ribbed.

You will get much more waste heat from an incandescent bulb than from an LED element. If you go down to Home Depot and look at bulbs, say from a reputable manufacturer like Philips, you can get an 800 lumen bulb that consumes about 9 W. That's about as much light as you get from a 60 W incandescent bulb. The incandescent bulb consumes 60 W but less than 5% of that energy is radiated as visible light. The rest is waste heat.

https://en.wikipedia.org/wiki/Incandescent_light_bulb

The actual converter that produces whatever voltage is required to drive the particular LED product from the car's provided voltage (12 V nominal) can be made efficiently too. That's why the little brick in the wiring leading to the LED has hardly any heat-dissipating features.

The fact that LED elements have heatsinks and incandescent ones do not does not mean LEDs produce more, or a higher proportion of, heat. They actually produce much less heat. It's just that the incandescent element is wasteful in itself and operates at high temperatures. Really, an incandescent lamp is almost a perfect heater, and it radiates a bit of visible light as well.

You can get LED products in various quality levels. Some will burn out quickly, like those cheap-o Christmas lights from no-name brands that you seem to have to replace every year. But if you get high-quality stuff you'll be happy.

I use Philips LED fog lights in my 2018 Forester.
 

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2010 Forester 5-speed manual
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169 Posts
Botnik,

Thanks. No argument here. I could have made my point better about heat. My point should have been more focused on the need to have a heat sink in the first place as opposed to a light source that does not require one in an automotive application. In my formal automotive trade days I have known people to brand themselves with high output H4 bulbs and even Solex Carburetor Choke heating elements. So yes, I know lamps, even CFLs, get hot.

With only a few exceptions, where I still have still have CFL bulbs that have yet to burn out, I converted my entire house that I bought when I moved to New York from my native Northern California a few years ago to Philips LEDs, except for the main bathrooms where I used Home Depot's house brand because Phillips did not have at the time suitable PAR40 replacements for the 25 year old 6" incandescent cans that were installed.

The principle reason I did so is that New York State's deregulated energy market make for energy costs that are significantly higher than California (even though my city here in NY mandates 100% wind generated electricity and there is a nuclear plant not far away) and energy efficient options are fewer here, though there have been some improvements of late. The important reason I switched wholesale to LEDs is that recycling e-waste properly here in New York where I live, the greater metro NYC area, as is recycling in general, is - to be polite - primitive at best. In my last California home before coming to New York most of our energy savings were through the use high efficiency major appliances, task lighting in the kitchen, and then the selective use of lights elsewhere in the house when ambient light was insufficient.

I am not fond of most of LED lighting in automotive and roadway applications. They seem to me to be too high in Kevin to the point of glare, over saturation, or washout when used for colored lights, and too bright for low beams especially when used with driving / fog lights as part of a needless use of a moving vehicle as a "wall of light" in urban-suburban driving environments where "city lights" would be the norm if we were as "bright" as the Germans.

I have an 2018 VW Alltrack S for the sole reason that it is the only version of the Alltrack that does not have a sunroof. It comes only with conventional driving and fog lights. The taillights are LED. I would have been happy with incandescent taillights if the rear turn signals where amber, which is more important than having the standard American all red taillight assembly in LED, in my view.

I only drive VWs and /or Audis as my personal cars and all in the last 20 years have had fog lights, which on say my former 2012 Golf TDI and the Alltrack serve as turning lights too. Other than that function, I rarely use fog lights, though I like to have them on my vehicles. Maybe I will convert them to LED at some point in the future.

The Forester I bought my oldest daughter does not have fog lights and I most likely will not install any. After market LED headlamps are far too expensive to justify installing them, if even possible and neither Philips nor OSRAM make them for either vehicle.

Regards
 

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2018 Forester XT Limited CVT
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I still have still have CFL bulbs that have yet to burn out, I converted my entire house that I bought when I moved to New York from my native Northern California a few years ago to Philips LEDs, except for the main bathrooms where I used Home Depot's house brand because Phillips did not have at the time suitable PAR40 replacements for the 25 year old 6" incandescent cans that were installed.
When we bought our current house, I replaced all the incandescent bulbs (including the head burner reflector incandescents) with CFLs. I think the last one died some years ago. They have all been replaced with a combination of Cree and Philips LED bulbs, however we have had a lot of failures with the Cree ones (some Home Depot-branded ones are made by Cree). The Cree ones also flickered a lot and had bare-bones/cheap power supplies (labelled as "instant on" -- meaning no filtering). We also added some recessed housings in various places. Cree's commercial products (from their paperwork) look okay. I don't know why their consumer products leave so much to be desired.

Fluorescent lighting is a technology that never should have taken off. All the buzzing, flickering, colour changing (a lot of fluorescent lights change colour with the phase of ac input -- makes for a lot of editing your photos after they are taken).

I am not fond of most of LED lighting in automotive and roadway applications. They seem to me to be too high in Kevin to the point of glare, over saturation, or washout when used for colored lights, and too bright for low beams especially when used with driving / fog lights as part of a needless use of a moving vehicle as a "wall of light" in urban-suburban driving environments where "city lights" would be the norm if we were as "bright" as the Germans.
If you look at the chart showing "combined light sources" we see that the LED is the best approximation of sunlight.

https://www.comsol.com/blogs/calculating-the-emission-spectra-from-common-light-sources/

If you look at a parking lot or intersection lit with LEDs, it is much more natural looking than one lit by eg sodium vapour. It would be wrong to go back. However when the light sources are closer to where you're looking (as opposed to being overhead) we do have to be careful about glare and collimation. It's easy to give the LEDs a warmer colour by putting the appropriate phosphor coating on.

I have an 2018 VW Alltrack S for the sole reason that it is the only version of the Alltrack that does not have a sunroof.
I've had cars with and without sunroofs. My previous car didn't have one and I thought I'd miss it but I didn't. My current car has one and the only time I open the sun shade is when it's quite cold out. If I open the sun shade at any other time it just feels like I'm burning.

rear turn signals where amber, which is more important than having the standard American all red taillight assembly in LED, in my view.
I don't think it's important at all, that is, an importance of absolutely zero, to have the all-red taillight. That's just cosmetics, and function is more important. When we install trailer wiring in our cars, the world has to work backwards, converting the sane taillight wiring with proper amber signals, to all-red for smaller trailers.

I rarely use fog lights, though I like to have them on my vehicles. Maybe I will convert them to LED at some point in the future.
I use fog lights a few times a year, probably fewer than 10 times a year, so there wasn't a real need to swap out the incandescents for LED, but after the swap I was much happier with the performance of the fog lights.

My wife had an A4 and I thought it was much nicer than my Civic, but since then I've had two Foresters, and I prefer the Foresters to the A4, and to the RX350 she now has.
 

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2010 Forester 5-speed manual
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If you look at the chart showing "combined light sources" we see that the LED is the best approximation of sunlight.

https://www.comsol.com/blogs/calculating-the-emission-spectra-from-common-light-sources/

If you look at a parking lot or intersection lit with LEDs, it is much more natural looking than one lit by eg sodium vapour. It would be wrong to go back. However when the light sources are closer to where you're looking (as opposed to being overhead) we do have to be careful about glare and collimation. It's easy to give the LEDs a warmer colour by putting the appropriate phosphor coating on.
The sodium vapor lights came on the scene in Northern California to save money due the the energy crisis of the 70s and the tax revolt led defunding of local government mania of the early Prop 13 era. They only went away with the advent of LED street lamps. they converted my city here in New York and the adjacent villiages two years ago. The main road that passes my neighborhood they over lit with too powerful and poorly shielded LEDs, but curiously on my street the did a very good job of duplicating a pre-sodium vapor lamp conventional residential street light in terms of quality of light and brightness. Not too much nor to little. Which is good since I have a street light / telephone pole just off my driveway apron on the adjacent property line.



I don't think it's important at all, that is, an importance of absolutely zero, to have the all-red taillight. That's just cosmetics, and function is more important. When we install trailer wiring in our cars, the world has to work backwards, converting the sane taillight wiring with proper amber signals, to all-red for smaller trailers.
The problem is cheap bare bones to the minimum trailer lighting. My brother-in-law, who lives in France, has amber turn signals with separate tail and brake lights on a small single bike motorcycle trailer. The norm in Europe. In a see of red tail lights amber turn signals are simply the way to go. But well this is the states....


My wife had an A4 and I thought it was much nicer than my Civic, but since then I've had two Foresters, and I prefer the Foresters to the A4, and to the RX350 she now has.
I had two A4 Avants w/ manual trans., a B5 and a B6. The B5 was totaled by a neighbor while parked in front of my house. So I got a B6. My needs changed and I traded the B6 (1.8T 6-speed) in for a new 2012 Golf TDI 6-speed. The B6 was far better than the B5. I miss both A4s, but the torque of the TDI I miss the most. If I lived in Europe the A4s would have been TDIs too.

Though lacking the torque of the TDI, my 2018 Golf Alltrack feels almost as quick as my B6 did with very similar horsepower and torque figures to the B6, but completely different AWD systems and drive train layouts. Other than the lack of a diesel engine, I am quite pleased with the road performance of the Alltrack.

In selecting an AWD vehicle for my oldest daughter (she did not want a wagon or a truck) and her pending career, I found 2010 Forester to be the best available SUV for her and my budget, especially so because of the availability of a manual transmission, though only a 5-speed. I find it basic, simple, and a bit under spec'd for being in Premium Plus trim, but not a bad ride in the least.
 
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