borland

I completed this LED turn signal mod on my 90’ S4 a few months ago, but never posted the results.

I ended up with:

-installing 1157 dual filament LED bulbs on the front corners,
-stock incandescent bulbs for the rear turn signal lights (single filament), and
-replaced the flasher relay euro LED flasher relay.

Since the front also serve as marker lights and are monitored by the bulb control module you need to mod that as I have posted the "how to" in the link below.

Most new cars equipped with LED brake lights still have incandescent rear turn signals, so not totally eliminating the rear incandescent bulbs is not a real concern.

The major problem I had encountered with placing LED all the way around was with the green turn signal indicator light on the digital cluster. Strange behavior of this green indicator light was the problem, with LEDs on the front only, the problem goes away. So, I'm happy with what I have now.

Very few 1157 LED bulbs available will work on the front for two reasons. First the socket are very deep with very little relief clearance; so you need a very thin LED bulb at the socket end. The other reason is the reflectors are highly curved, so you need a wide angle SMT LEDs, otherwise the LED bulb will not take advantage of the reflector fully.

Here’s the 1157 LED bulbs I installed..

http://cgi.ebay.com/ebaymotors/2-AMB...9747QQtcZphoto

And here’s a link to the euro flasher that I used:

http://cgi.ebay.com/ebaymotors/3-PIN...4781QQtcZphoto

Here’s the links to my previous LED mod posts…

for the brake lights…

https://rennlist.com/forums/showthre...&highlight=led

and side marker lamps…

https://rennlist.com/forums/showthre...&highlight=led

and disabling the Bulb Control Module for LED bulbs….

https://rennlist.com/forums/showthre...&highlight=led

And the license plate LEDs:

https://rennlist.com/forums/928-forum/334483-license-plate-led-bulbs.html

None of these mods required installing energy wasting load resistors.

chaadster

Very nice writeups, Borland. Thanks for doing them!

ew928

Thanks Borland.
I've got a few 1157 LED's that were to fat in diameter to seat into the front turn/park bulb socket. The LED bulb cannot have a big lip right on top of the bulb base (metal cylinder that goes into bulb socket).
I'm using regular LED array bulb but may try the SMT bulb.
The front corner marker is tricky as any bright LED bulb optimized to throw out a good forward beam will not light up the reflector and will not be seen well from the side. You sorta want people to see the turn signal from both front and side.

And so my collection of bulbs may yet grow.
Still waiting for more high brightness Luxeon LED's to reach the market . . .

Bill Ball

Ern, for the clear front sidemarkers, I used a 15 LED amber 15mm bayonet bulb that has 6 of the LEDS shooting outward. Ed Scherer suggested it. It lights up the whole lens as evenly as the incandescent bulb. If you are still using amber lenses then a white bulb will work, of course. No change to the socket - dropped right in.

You can find the bulb here by entering 67 15-LED in the search box at the top of the page.
http://www.superbrightleds.com/cgi-b...gi?product=CAR

ew928

Hi BB,
I'm thinking the SMT ones in amber may be brighter. The red LED bulbs I used for the rear cluster worked really well. The white ones seem to not show up as nice.

The search you gave shows up as 1156 single filament replacement? Don't we need the 1157 type dual filament bulb replacment? The bulbs they had are nice and skinny and work well in that small space for the front corners.

Bill Ball

Ern, I thought you meant the front (side)markers. If you mean the combo turn signal/front marker, then yes, that is an 1157. I have not replaced those and probably won't. However, for the sidemarkers, I didn't want anything brighter than the original bulbs, and the ones Ed suggested work absolutely perfectly there.