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Discussion Starter #1 (Edited)
Most of the mods that I have done to my car have been in the vain of modernizing the car with upgrades that current or at least newer Benz's have. One of the main things is lack of a factory Keyless Entry system. There are several on the market, including one marketed here locally. But I was not happy with any of them. Then I was surfing FleaBay and found this one. (I have NO affiliation to this company at all. I am just a happy customer)

It was only about $50.00 and it specifically said it was for pneumatic systems, so I took a chance. Our system needs a more than 2 second pulse of either +12 or ground. This unit does that. There is a jumper on the side of the unit to select lock type and delay. They contacted me very quickly and asked which car badge and key style I wanted and I told them and the unit was on the way. I got it about a week later. Typical Chinese packaging, but the Key FOB's were very nice. Very solid.

Since I have been all over the wiring, and I also had the drivers door open, I knew where things were and easy power was at the X-30 block. For those of you who do not know what the X30 block is, read HERE. I decided to place the unit in or near the passenger footwell electronics bay. My bay is pretty full since I added the SAT Radio and GPS/NAV system, both of which are located there. There was a little room so I placed it there and did my measurements for the harness. A 4' power harness to the X-30 and 3' to the door post and the supplied wires for the flashing lights and the horn signal were suffice. The plan was to tap into the Hazard lights and into the horn switch. That way everything would be short runs of 3' or less.

Here is the head unit with the homemade harness and the reciever wire and the lead for the LED:


Here is the power connector (The black plastic connector that plugs into the X-30 block) and the green and white wires that go to the vacuum pump to actuate the door locks:


Here is the blue activation LED and the 3 wires are for the lights and horn:


Here are the Key FOB's: They come with blanks, but I am going to grind down factory keys because they are stronger.


Here is my drivers door open to reveal the harness coming forward from the door locking mechanism.



If you open the shrink seal for this harness you will see a solid blue wire. This goes to the Vacuum pump in the trunk. It also sends a signal to the Alarm controller too. If you are good you can tap into that signal there, at the alarm. I used this to tap in for the door lock button that I also installed.

The way the door locks work is very easy to under stand. There are three wires that trigger a lock/unlock command. Blue for the drivers door, green for the passengers, and yellow for the trunk. There is a +12 supply lead to each lock and also a ground. When you turn a key in a lock to the "Unlock" position, you close the circuit to the +12 side and you send +12 to the pump. That signals it to actuate in the unlock direction. If you turn it to the lock position, you send ground to it, and the motor reverses. The KES takes +12 from it's own power source and also ground and when you push the appropriate button on the FOB, it sends +12 or ground to the pump. You just have to tap into one of those three wires.

The easiest place is to find them is on the alarm box. They are pins 4, 5 and 6 on the larger 14 pin connector. If you tap in there, then you only need the white lead. If you tap in at the door wire, you need to hook up the other side of the circuit so that if the key is used, it retains that function. If you tap in at the Alarm, you only need to send the voltage or ground and the pump will pick it up. So if look at the supplied schematic, if you tap in at the alarm, you only need the white wire and you do not need the Orange/Back wire. You only need that wire if you cut inbetween the pump and the key.


I installed my KES control box right next to the alarm box to make it easier


I wanted the car to signal if you lock and unlock it, and I wanted the "Lost Car" function to work, so I had to tap into the lights and horn. The Hazard switch provides quick access to the corner lights and the "City/Country" horn selector found on 560's makes access to the horn just as simple.




I opened up the plastic holder and soldered the wires to the molex connector for a solid connection. On the Hazard you want the Black/White and Black/Green wires. They go to the corner markers. Careful when you take the connector apart. You could use a splice if you wanted. On the horn switch you have your choice. Above the switch on the middle Black/Violet wire will chirp whichever horn you have selected at the time. Or the Black wire for the "Fanfare" horn and the Bl/Pi/Vi wire for the "Two Tone" horns. Then it will always be that horn no matter what position the switch is in.

If you do not have that switch, you will have to run the wire out the firewall and to the horns directly. The grommet comes out under the battery tray.

Drill a hole for the LED or use that hokey surface mount, but the rest is cake.

If you are handy with a grinder, you can grind your existing MB keys down so that the stub fits in the FOB. I'll post pics as soon as I'm done with that part. And also some vid of it working. The corner lights flash and the horn chirps when you lock or unlock the car and the car finder works great! I am VERY pleased with the results and should have done it a while ago. The KES has a bunch of other functions and I am going to build in a FPR disable too as an added safety measure.

It a simple but effective mod that pretty much anyone can do over the weekend. Enjoy!
 

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Discussion Starter #4
Wow! Good work.

I just ordered this "plug 'n' play" W126 unit --->
Yeah, that's the one I was alluding to in my first post.
 

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I just received the exact same keyless entry system today. Took about 12 days to get here from the UK. I also ordered the auto window up/down module with the keyless entry unit.

mclare, Thank you so much for suggesting this particular unit because I am very pleased thus far and I don't even have it all hooked up yet. I have the horn/turn lamps hooked up and still working on the White wire to the alarm module in the passenger footwell.

This is indeed a very forward and simple unit to install. The key fobs seem to be of very good quality.

I will probably tackle the auto window up/down unit sometime over the weekend.
 

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Discussion Starter #7 (Edited)
Steve,

Don't forget to put two Diodes in parallel for the Flashers to work correctly. You need them for bleed back. You may need them too for the windows. I wouldn't be surprised if you did.

Send m the schematic for that module and I can tell you if you do. I didn't add that feature to mine. Someone had done that to this car before I got it, and I spent a month trying to extract that wiring from the car when I first got it, so I wasn't too motivated to put it all back in.

Are you going to do the sunroof too? That will be a challenge to wire that in. Prolly best if you only do auto-close on that, and not open too.
 

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Steve,

Don't forget to put two Diodes in parallel for the Flashers to work correctly. You need them for bleed back. You may need them too for the windows. I wouldn't be surprised if you did.

Send m the schematic for that module and I can tell you if you do. I didn't add that feature to mine. Someone had done that to this car before I got it, and I spent a month trying to extract that wiring from the car when I first got it, so I wasn't too motivated to put it all back in.

Are you going to do the sunroof too? That will be a challenge to wire that in. Prolly best if you only do auto-close on that, and not open too.
mclare, the unit I received today had built in Diodes on the brown wires leading to the hazard switch, hazards and turn signals function flawlessly as they did before. Do you still recommend I add more inline Diodes? Did the unit you installed have the Diodes on the brown wires?

As cool as it might be to do that I will not be wiring the sunroof into this system, as you say it would be a challenge.

As for the auto window feature, the module I have is designed exclusively for use with this keyless entry system. I am not sure if any relays/Diodes would need to be installed with this unit but I will send you the schematics and you can tell me if they need to be added or not.

Thanks for the help mclare,

Steve
 

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Discussion Starter #10
Thanks Ross.

Steve - If it has the diodes, you don't need two. Only the one each per side. If they work and you are not getting cross bleed, then you are fine.
 

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Hey Mike,
I am just about to order the same one as you. However which key code did you choose for the key blanks. Does it matter. I have an 87 560sec stock. Could you please advise me of the right key blank to choose? HU 39, HU 64, HU 41, YM 15, or MB 39? Thanks again Mike.
 

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Discussion Starter #12
MB39 I think?
 

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Thank you, I'm ordering one soon to install into my Pegasus project. And I love the X30 connector.

BTW do you have a write up or pictures of the Sat Nav system? I'm in the process of swapping out interior from one W126 into another and looking to create some upgrades.
 

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The key blanks for the W126 are actually HU39 or atleast those are the key blanks I received with my fobs however, as mclare suggested I am not going to use the ones that are supplied with this kit but rather take 2 of my newly purchased keys from the dealer and grind them to fit the fobs.
 

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Great write-up, Mike!

If I ever get through dealing with this money-pit of a house, I'll definitely look into doing this for the 500.

Regards,
Josh
 

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Sorry an older post, I just wanted to check and see if all w126's have the Vac pump that works this way. I just don't want to buy this and pull the door apart to find out it wont work. Most that have posted are gen II W126's. I have a 1985 300sd just want to make sure before I purchase.

Thanks in advance
 

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The central locking on late gen 1 and gen 2 use the vacuum pump. Early Gen 1 need to have a soleniod installed in the drivers door to operate the locks.

If you can unlock the central locking from the passenger door then it uses a vacuum pump.

I hope this helps



Sent from my iPhone using AutoGuide.com App
 

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I can unlock the car from the passenger side, so does this mean I still need the solenoid.
 
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