[VickyK]

Built this long time ago, just got time to write it up.

Basically I was keen on a homelink module , although there are existing ones for E90 which is mounted on the rearview mirror, there is various makes and the ones support HBA [high beam assist] are very expensive, like absurdly.

Didnt want to waste money on a simple gadget, so i decided to custom make one for my E90.

It uses a generic homelink module which can be found in various car makes, I modified a E39 seat memory switch [You can use any switch that you like, as long as it can sit under the center console] and soldered the pins together, dremel'ed into the centre console , wired up and pretty happy with the outcome.



Step 1- get some standalone homelink module, ebay is your friend. It has 2 pins, generally, power and ground. I got mine for like $40 bucks only.

Step 2 - Open up E39 switch and desolder the connection by removing diodes and resistors. You have to trace the pinouts and make mini jumper cables on the board.



Step 3 - Open up the homelink module and locate the contact swiches and common ground. [You need to be cluey abt using a multimeter at least]

Step 4- I used a CAT5 network cable for interconnect the switch and homelink. Because in total, I require 8 wired connection and the CAT5 network cable is the most ideal. Solder the wires on the Homelink module and have a Cat5 Male end. On the E39 switch, solder /join the cables with and have another Male CAT5 end. The intention is so that these 2 units can be seperated using a CAT5 extender dongle if needed at any time. Below is the connection pinouts:


Note: You dont need these many pinouts or lighting if you plan to just use a regular single switch, which in that case you need just 2 cables tapped to the homelink. I just made a full use of the E39 switch and lighting to make it look OEM.

Step 5. Test. I used a 12V power supply and tested out the homelink before installing it into the car. Worked fine, except i noticed the switch started heating up. Thats when i realized i needed to add a limiter circuit into the switch lighting circuit. 12V that goes into it, you need to add a single way diode +2kiloOhm resistor in series before it hits the light circuit. That solved the problem.


Step 5: Installation in car. Disconnect battery and remove center console. I tapped power, ground, and lighting from the cigarette lighter area, as its the most practical and thats all is needed.



Step6: Mark the dimension of the E39 Switch on the center console where you will be using a dremel tool to make a hole. Make sure its in the center spot between the border and Idrive switch.



Step 6: Snuck the Homelink module inside the center console, right at the very end. Wire up the power connections. Put the E39 switch on the hole you just made, Join the CAT5 inteconnect and attach the homelink in the other end. Asemble back the center console trim, plug back the battery and you are done.

Now you have a working homelink module , ergonomically positioned as well as economically practical. Since the switch is from another beemer, when you turn on the lights, it matches the amber colour with the rest of the car.

Video of it in action: