I solved the LED indicator problem!!
 

Hi there my fellow Pelicans. I have over the last couple of weeks been trying to find a solution to the common problems you get when fitting LED bulbs to the indicators on our cars without having to fit the nasty resistors (which puts back some of the problems I was trying to solve - reduced current on the circuit and wires!!). Now that I have completed the project and tested it, I would like to share this simple upgrade with you all, should you wish to do the same :)

I should point out that this was done on my 78SC, which has the 4 pin relay (Pelican P/N: 914-618-303-11-M44 "Hazard Flasher/Blinker Relay, 911 (1974-84)) and not the 3 pin version as found in the 1985-89. I would have to see the circuit diagram and more info on these to know if this upgrade would work.

Parts List:
.- Replacement LED indicator bulbs. NOTE: You must replace all bulbs or you will burn out the new relay!!!
.- 1x BMW LED Flasher relay (this is the one I got: http://www.ultraleds.co.uk/product_info.php?cPath=44_64&products_id=978&osCsi d=8a3d27c6ff8ba53dabbf9d69bedc8125)
.- 2x female spade terminals (http://www.cybermarket.co.uk/ishop/923/shopscr2376.html)
.- 1x female spade piggy back terminal (http://www.cybermarket.co.uk/ishop/923/shopscr2388.html)
.- Some brown wire.

Project:
1) Remove and replace all the indicator bulbs with the new LED ones. I would do this first!! If you should do the relay first and decide to run a test with the existing bulbs still connected, the current will burn out the new relay :(

2) Pull out the two left most gages in the car (fuel level and oil pressure).

3) Locate the correct relay and pull it out. A quick way to do this is to turn on the hazard lights and touch the relays - the one that is clicking is the one you will be replacing.

4) Put the new BMW relay in the socket - make sure you do not bend any of the pins. There is not a lot of space in there!!

5) Test your indicators - The hazards and the indicators should now work as expected. The only problem left is that the left and right indicators in the rev-counter will not light up. This is because you have removed that part of the circuit (the 4th pin on the relay!). Not to worry, that is what the additional component are there to fix :)

6) If you look at the back of the sockets for the left and right indicator bulbs in the rev-counter, you will se that they both have two wires attached to them via spade terminals. Using the new terminals and extra wire that you have, you are going to replace the part of the circuit that feeds the signal back to the missing relay pin so that it goes to earth (negative terminal on the battery!!). Good news is that you can do it all on the back of the rev-counter :)

7) Disconnect the blue/white wire from both the bulbs, and tape up the ends. I opted not to cut the wire so that I had the ability to revert back to a factory relay if I ever want to in the future.

8) Make up a new cable containing three spade terminals in the following way: [female spade terminal]--------------------[female spade terminal]-----------------[female spade piggy back terminal].

9) connect the first spade terminal to one of the bulbs (the terminal you removed the blue/white connector from), the second spade terminal to the second bulb (again the terminal you removed the wire from). Then remove any of the connectors at the bottom of the rev-counter with a brown wire going to it. Put the last female spade piggy back terminal in its place, and reconnect the brown cable to the piggy back pin on the new terminal.

Job done - your new LED indicators will work, and the bulbs in the rev-counter will also work as expected.

Nice work! :cool:

Thank you Chris...

I think I may have a different problem with my install. This is on my 77. I replaced all the incandescent bulbs with the correct LED (45 towers) and the new flasher relay.

The turn signals work properly with one exception - the other side (the side that should not be blinking) also blinks, albeit more dimly. Restated - when the left flasher is working, the right side (front and back) also blink dimly. Same when the right signal is activated. It is easy to tell which is brighter, but it still looks like I have hazards on rather than turn signals.

Any clues?

Congrats on your work, Good Job.

Question: Can you take a picture in the day light with the lights on? Preferably during mid-day sun. Maybe a video to capture the full flash aspect?

I had issues where it would not completely fill out the lenses.

Jim

If you found the answer please let me know, I have the same issue with my 78 and i'm not going to rewire everything to get brighter signal arrows in my gauge...

Gary,
I'd love to see your silver 78 some day. Sounds like we have almost the same car!
Nick

thanks for postimg this. would you be willing to draw up a basic wiring diagram and/or pics? i am doing this on a car that has zero wiring harness in it now.....

thanks!

This is how I did it. This is how my "harness" looked when put together.

http://forums.pelicanparts.com/uploa...1400092918.jpg

As the description above states, I then unplugged the blue with white stripe wire in this pic.

http://forums.pelicanparts.com/uploa...1400092968.jpg

I then connected the 2 spades in place of the blue with white stripe wire. I then pulled the ground wire off at the bottom of the tach, plugged in the piggy back spade in the original ground's slot, and then plugged the old ground wire into the piggy back.

I have a set of ETarga's LED's in my indicators. At first, only 1 indicator lit up. Playing around, I don't think I had 1 of the indicator LED's plugged all the way in. I pulled them out but then pushed them in as far as I could and they both worked, but they then worked in opposites, so I reversed the live end of the circuit on the indicator bulbs and everything works perfectly.

Well Done

I'll try putting them in again and shoving them in further. On mine they are either on all the time, blink in the wrong direction, or do nothing at all depending on which way I flip the bulbs... again, original bulbs work fine..

:)

The link to the BMW LED flasher relay does not work for me.

Can you give us the Part Number from BMW? Must be available here in the USA.

Len

:)

I think this is the flasher link:
http://www.ultraleds.co.uk/complete-led-flasher-unit-stops-fast-flashing-led-indicators.html

Can you post a picture of the LED lights you are using?

I am on the same quest, replace indicator, brake, and parking lights with LEDs. The lights I bought work with out any modifications to my wiring. Problem with these lights is they are too directional, the beam is not bright off center.
http://forums.pelicanparts.com/uploa...1400382768.jpg

Not to hijack, but I think that having the heater fan, fuel pump, ignition, brake lights, blinker relay, and backup lights on one circuit from the ignition switch to be problematic. I am going to add a new power source (new wire and fuse) and shift some circuits off of the ignition switch circuit (fuse #7 and #8). I have a 71 so my electrical may not be the same as your SC.

I plan on starting a new thread on this once I work out the details.

Post the link here so we know you started it! :)

Kroggers,
This is great and I am glad you posted it.
I also have a set of ETarga's bulbs which I am very happy with. When I replaced the brake and indicator lights I had a hard time make the bulbs fit securely. I read were some guys put some electrical tape around the base of the bulb, but I had no success with this idea.
What I did to resolve the loose bulbs is to use solider and build up the very tip of the bulb, right at the source contact. It didn't take much and the result was perfect. The bulb now hits the spring loaded contact with a little more depth with the result being the bulbs fit tighter and don't lose contact when bumped. Now you don't need to mash them in.

Happy driving!!

Very good idea. I used a dental pic to reach into the sockets and pull the metal contacts out a little further.

Len,

I bought my flasher relay from superbrightleds.com, but just checking now, they have none listed.

For my exterior indicator lights, I bought LED clusters like this, using the appropriate color and model for each location.
1156 CAN Bus LED Bulb - Single Intensity 26 SMD LED Tower | LED Brake Light, Turn Light and Tail Light Bulbs | LED Car Bulbs | Super Bright LEDs

Len,

If you do the blu/wht wire ground mod discussed above, a EP26 solid state flasher works perfectly. Sometimes you can find them at auto parts stores. I bought mine on line.