MyE28.com

Homelink E28 Install
by Brad Denton

Purpose:

Many new vehicles come with Homelink installed. It offers a high level of convenience and security by consolidating all of your "openers" and prevents you from having to leave them in your vehicle. Since the e28 was never blessed with the convenience of Homelink, I decided to retrofit a modern unit into the car and have it look discreet.

The Install:

The Homelink modules are standardized regardless of the vehicle they are installed in. Only the buttons vary. The unit that I used was purchased on ebay for $15 and was from a Lincoln vehicle.

(The grey wire exiting the right side is the remote button wire that I added. It is not part of the original unit.)
Make sure that the unit that you purchase is a later model that is compatible with rolling security codes. Early units will not work with many new gates and garage doors. The unit is very small, only slightly larger than a deck of cards.
The unit only requires switched 12V and a ground making a basic installation very easy. While I could have used the existing buttons and bezel, which actually matches my llama interior quite well, I wanted a more discreet set of buttons and did not want to cut up any of the interior to mount the unit.
My solution was to bypass the on-board switches and remote mount them by using a factory BMW window switch. Any momentary switch would work though. Since the window switch only has two buttons, you can only control two devices. I chose to use the outer buttons so that the unit can be programmed from the remote buttons. Here is the board and the location of the remote switch wiring. There are existing solder pads which make adding wiring very easy. I used a run of two pair shielded wire to make for a clean wiring run to the switch. I mounted the control unit above the glovebox with some double sided tape.



-Button Modification:
The factory operation of the BMW window switch is not optimal for operating the Homelink module. The contacts share a common power pin and switch the other pins between power and ground. I wanted two independent switches so internal modifications were required. The image below summarizes the changes made inside the switch.



Since the contact wipers are now changed the button on the side with the bent vertical tab needs its contact bent inwards so that it will not interfere with its operation.



I mounted the window switch next to the radio in the location where the original fader used to sit. It is right at hand and looks very factory.



Programming:
Programming the unit is extremely easy. For the first time of use turn the ignition on and hold down either the two outer buttons or your remote switch buttons for approximately 20 seconds until the led flashes rapidly. This clears any old codes stored in the unit. To program hold down the button for the channel you wish to program and simultaneously hold the button on your original transmitter. Do this until the light flashes rapidly confirming that it has stored the code. If you have a garage door with a rolling code you will now need to sync up the devices. Press the "learn" button on your garage door or gate unit and then press the button that you previously programmed and it learn the new transmitted code and everything should work great.

Conclusion:

This is one of the best simple mods I have made to my car. For less than an hour of my time I have added a high level of convenience to the car. It works extremely well and looks very stock. For less than $30 (depending on what you pay for your unit and switch of choice) it is a great upgrade and would recommend it to everyone!

That is awesome.

Now I just need my own garage...

Well done. I'm sure that if I decide to pursue this, I'll have more questions.

What I thought was odd is that we've had some Dodge Caravan rentals and they have it in the visor.

wkohler wrote: What I thought was odd is that we've had some Dodge Caravan rentals and they have it in the visor.

There are a fair amount of cars that mount them in the visor. I think the one I got was too. The whole module is in the visor which gives you an idea of how small it is.

Nice idea, you could also clean the graphics off the buttons I suppose and find a way to put a picture of a garage door on there! But what is that non stock box next to the temp control dial. That needs to go under the ash tray lid or somewhere discrete now.

On our 535 there is an old e30 defrost switch with the graphic worn off to the right of the radio. That is used to cut the signal to the power antena since the radio is rarely used for radio. To the left of the radio is where we relocated the window CB to make it more convenient.

tn535i wrote:But what is that non stock box next to the temp control dial. That needs to go under the ash tray lid or somewhere discrete now.

That is my boost controller. I've been meaning to put it somewhere a bit more discrete but I like having it at hand and I have another plan for the ash tray location. 8)

Big Bronze Rim wrote:

tn535i wrote:But what is that non stock box next to the temp control dial. That needs to go under the ash tray lid or somewhere discrete now.

That is my boost controller. I've been meaning to put it somewhere a bit more discrete but I like having it at hand and I have another plan for the ash tray location. 8)

YAY! Another upcoming Brad FAQ!

Wow, good work Brad...

Just switch out to an e24. There is usually three of those extra pushbutton locations to which you can add important stuff.

Didn't have any idea what homelink was until i read this DIY looks like handy!

Nice write up here BBR.

Awesome. I need to do this. I hate moving the opener from car to car.