Led bulbs in 348 tail lights

Hello people,

First of all, I will apologize for posting yet another thread about this topic, but after searching around, I got even more confused... so here I am asking you for advice!

I would like to replace the tail light bulbs in my 348 with LEDs. The motivation behind choosing LED is that they last longer and run colder, so no issues with potentially melting the housing.

I have been able to retrieve the following information regarding the OEM bulbs so far:

- Rear position light: 3x 1156 bulbs @ 5 watt
- Rear braking light: 1x 1156 bulb @ 21 watt
- Reverse light: 1x 1156 bulb @ 21 watt
- Rear fog light: 1x 1156 bulb @ 21 watt
- Rear indicators: 1x 1156 bulb @ 21 watt

So all in all, two kinds of bulbs are used: 1156 @ 5 watt and 1156 @ 21 watt

After checking many conflicting resources, I have been able to figure out the following figures about the OEM bulbs:

- 1156 @ 5 watt produce ~35 lumens
- 1156 @ 21 watt produce ~440 lumens

While checking about how to correctly replace OEM bulbs with LED, I have found that it is desired to buy bulbs that match the color of the housing, rather than buying standard white bulbs. That's because LEDs produce light in a very narrow spectrum, and therefore, the coloring of the housing will filter out most of the light.

The problem that I am having now is that most of the replacement LED RED bulbs that I find on internet fall within the 75-350 lumen spectrum. That means, they aren't really suitable for neither the original 5watt bulbs, nor the 21watt bulbs.

I am sure that some of you have already gone through this investigation process... so can you guys recommend LED 1156 replacements that are suitable for both 5W and 21W applications? Would you also recommend to hike up slightly the lumen output, as compared to the OEM bulbs?

Thanks in advance for your input!

 

I have replaced only the 3 x 5W bulbs with LED (SMD type). However, even the smaller (shorter, 2 "storey") ones were too bright for this application so I inserted an external resistor for each bulb (82 Ohms, 2W) and this brought the intensity to the correct level. You will have to find suitable value of the resistor for the type of bulbs you decide to use.

I have tried the 3 "storey" LED (also SMD) for the stop lights. I did not check its lumens, but it is at least as bright as a classic 21W bulb (in my own judgement/observation, it is brighter). At the end, I decided not to use LED-s for stop lights to avoid warning light "blown stop light bulb" and because they are not used for very long (with manual gearbox).

 

You've just confirmed what I have been suspecting all along... there aren't many off-the-shelf options available out there that are a suitable replacement for the 5W bulbs. Such a bummer...

I really wanted to avoid using resistors, since they need to be placed somewhere, and also because I am fairly bad at electronics

Anyway, thanks a lot for your input!

 

I wasn't aware that the 348 has a lamp failure warning circuit. Where is the warning lamp? I want to look for it in my car.

BTW, I swapped the interior lamps in my TS for warm white LEDs and the result is fantastic. Will start a thread on that one of these days but that's why I'm fired up to convert some of the external lamps.

 

There isn't a lamp failure circuit on the 348 as far as I'm aware (and according to My owners manual).

When it comes to warning lights for the braking system you have:

"Brake warning light" (red) for low brake fluid level/low booster pressure.

"Hand brake and front brake pad wear warning light" (red) for the hand brake being on or the front brake pads being below minimum thickness.

"ABS warning light" (amber) for warning of an ABS system fault.

And that's it - There's no "Brake light failure warning light" or any other lamp failure warning light on the car.

(I stand to be corrected, but believe I am right on this).

 

I wish a wizard from the Brotherhood would engineer something similar to what spokeworks has been doing for the pre-89 911. Hard to capture in pics, but looks great in person and makes a big difference. Also helps that those cars have removable lenses, you can see pics of my blue car towards the end of this page: spokeworks-led

Is there the possibility of doing something similar for the 348?

 

Looks like I forgot what I actually did. Went and checked: I also put LED-s for the stop lights; didn't use LED-s for the fog lights (no fog in Malaysia), nor for the reversing or indicator lights as these are used for short periods of time. So my "theory" about bulb failure warning is out (it was probably a reason in the case of one of my other cars).

 

I'm relieved that there are others whose memories are as wonky as mine.

I was almost positive there was no lamp warning circuit in the 348 but my memory has hosed me before. Glad to see that my plan to replace the rear lamps with LEDs has not been thwarted. Thanks for the clarification.

 

Which rear lamps are you planning to replace, Mike? If you find a suitable replacement for the little 5W ones, let me know! I am very interested!

 

I'd like to do them all but I'll start with the major heat sources-- the brake and tail lamps.

www.superbrightleds.com shows replacements for the smaller park and license plate lamps but only in red, amber, and cool white. I want to maintain a period correct look so cool white will not work for the license plate lamps.

Note that if you do order anything from superbrightleds.com that you should check the application for yourself. They have perfect replacements for the interior lamps but they show incorrect sizes and part numbers in their online application guide. I'll send them a message once I get some pics of the improvement but it's always good practice to check for yourself to make certain what their selling for a particular application is correct.

I wouldn't get too caught up in comparing light output though. The output of the original filament lamps diminishes over time so the LED replacements will almost certainly be brighter. But since they're behind lenses it shouldn't be too obvious if they're a bit brighter than stock.

 

I bought my LED-s from Ebay seller 2x 1156 Bau15s Ba15s 30 5050 SMD LED Rear Tail Light Bulbs Ultra RED | eBay. These bulbs are declared to have "Approx. Lumen: 650~750". I have no complaints so far (bought quite a number of different shapes and sizes).

The pic shows the 3 sizes of the 1156. I used the 3 storey bulbs for the stop lights and the 2 storey ones (with resistors) for the parking lights. Tried the smallest ones for the parking lights but their light did not fill the lens fully and had still too bright but "spotty" appearance. The 2 storey ones are perfect with the resistors I soldered in-line.
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