Keyless entry -- W124 - Page 2 - PeachParts Mercedes-Benz Forum

Jeremy5848 · #16 05-11-2009, 12:03 PM

Quote:

Originally Posted by mplafleur

Can you be more specific on how you wired this into your pump? I have an '86 SDL and I hope I can assume your locking system is the same as mine.

I was under the impression that I would have to wire a solenoid into the driver door and there was nothing at the pump I could do.

I don't know if your S-class has the same locking system as my lowly pre-E-class . . . if it does, all you have to do is to access +12 volts and ground to power the keyless entry system and you need to break into one of the wires from a door lock. This can be either front door or the trunk/tailgate (as bobo said). The additional relays (easiest to buy the pre-wired accessory kit) allow the lock system to work normally with keys and knobs but also allow the keyless entry system to operate the locks.

You need to find out somehow whether the S-class lock system is the same as the lesser-classes. Maybe someone here will know.

Jeremy

bob_98sr5 · #17 05-31-2009, 11:53 PM

WARNING: One VERY wide picture!

Jeremy,

I was wondering if you could help me on my install. Its a different brand of keyless entry. I feel I'm close b/c the relays are clicking when I press the lock and unlock buttons on the remote, but the vac lock is not working.

I sent this to the alarm company yesterday, but if you can figure it out before them, I'd greatly appreciated. Their turnaround on an email is 2-3 days. Please see below:

Also, the manual calls for hooking up the starter wire to Relay 1 Pin 86 and Relay 2 Pin 85 to it. Is this the starter wire below? I could not find any other purple wires other than this one:

Thanks for any help!

ah-kay · #18 06-01-2009, 12:15 PM

bob_98sr5

I do not familiar with the alarm system you have but it looks like it is set up for cars with central locking. It has 2 relays arranged to give a pulse to trigger the actuators. I do not have access to your installation instructions so I am only writing based on my experience.

I have done a number of MBZ with keyless entry and it is quite easy. I use different brand for each MBZ as I bought them from eBay at various times. They all work on the same principle. Anyway, the unit has to be pneumatic capable ( vacuum ) for MBZ. There is a jumper to select pneumatic option which extends the actuation time to 3 sec, enable the jumper.

I think what you have done is not correct. You only need to cut 1 wire, the common wire. Then you connect the 2 wires from the keyless unit to each end of the cut wires. That is it. I do not recall what color of the wire to cut as it is a hassle to open up my cabling.

Another trick is to simulate the door open/close otherwise the unit may lock the door again after 30 seconds or trigger an alarm as it thinks the door is closed/opened. What I do is to connect one of the parking light wire to the door trigger(+), it would work for trigger(-) since the parking light is turned on/off a number of times. Connect the siren and you are done.

The reason I think you may be wrong is that the car in theory can still lock/unlock manually even with the keyless installed. In the picture, you cut 2 wires and here is NO way you can lock/unlock the car with the key manually at that lock.

I installed the alarm at the trunk lock void area. I can still lock/unlock manually at the trunk.

Please double check your wiring. Good luck.

bob_98sr5 · #19 06-02-2009, 12:19 AM

Ok, first off, Jeremy sorry for mucking up your thread

ah-kay, thanks for notes, it helped me think things through a little more.

Just a quick note on why my wiring went wrong: I did not use a crucial 3 pin harness that wires up to relay #1 post 86 and relay #2 post 85. the purple lines coming from that post that are erroneously connected together and then to the actual starter wire (another blunder) should not be going there. as mentioned, they singly connect to the blue and green wires on the 3 pin harness.

the other mistake i made was cutting two of the three wires off the round harness that goes into the vac pump. the one i was supposed to cut was the green one. once cut, solder relay #1 post 87a's line to the driver door lock end of the cut wire. for the other end of the cut wire, solder it to relay #2 post 30.

i extended the length of the stock antenna wire since it was too short. i soldered it to a 22 gauge piece of left over wire i had and ran it up the rear seat and across the back. i can open/lock my car now. i think this will definitely come in handy

...i'm going to check it one more time to see if it works

mplafleur · #20 06-02-2009, 07:32 AM

When you are done, please post a modified picture of correction.

Jeremy5848 · #21 06-02-2009, 01:03 PM

Just back from vacation . . . Bob, you and Ah-Kay are correct, only one wire, the blue driver's door wire, need be cut. The purpose of the relays is to (a) apply +12 Volts to the pump to lock, (b) apply ground to the pump to unlock [or is it the other way 'round?] and (c) to otherwise have the system act as if no wires are cut, you you can use the key and the button on the driver's door to lock and unlock.

It really helps to understand both how Mercedes engineered the system and how the lock people designed their relay mechanism. It took me quite awhile to catch on so don't feel back about making a mistake. Looks like you have it fixed now.

To fix the picture in Bob's post #17, all you have to do is to put the green wire back to the original factory configuration (cut only the blue wire). Leave wire (4) where it is and connect wire (5) to the other end of the blue wire (shown "hanging loose" in the diagram.

Jeremy

ah-kay · #22 06-02-2009, 01:19 PM

There is no need to fabricate your own relays if you don't want to. There are Universal Car Alarm with Keyless entry selling for < $30 in eBay including shipping. It comes with everything, siren, shock sensor, starter cutoff relay etc. I only use the siren. Just make sure it is pneumatic capable. Just following the instructions, cut 1 wire to the lock ( what I did ) or near the vac pump and you are done. It is the same wire anyway, just in different locations. It is not as difficult as one may think.

mplafleur · #23 06-02-2009, 04:19 PM

Quote:

Originally Posted by Jeremy5848

(a) apply +12 Volts to the pump to lock, (b) apply ground to the pump to unlock [or is it the other way 'round?]...
Jeremy

Yes, it is ground to unlock and 12v to lock.

bob_98sr5 · #24 06-02-2009, 06:50 PM

Ok guys, here's how it is, all correctly wired:

bob_98sr5 · #25 06-02-2009, 06:54 PM

Quote:

Originally Posted by ah-kay

There is no need to fabricate your own relays if you don't want to. There are Universal Car Alarm with Keyless entry selling for < $30 in eBay including shipping. It comes with everything, siren, shock sensor, starter cutoff relay etc. I only use the siren. Just make sure it is pneumatic capable. Just following the instructions, cut 1 wire to the lock ( what I did ) or near the vac pump and you are done. It is the same wire anyway, just in different locations. It is not as difficult as one may think.

ah-kay,

can you post up an example? had i known, i most likely would have gone the relay route. monkey see (on forum), monkey do

ah-kay · #26 06-02-2009, 08:37 PM

http://cgi.ebay.com/Universal-Car-Alarm-W-Sleek-Remote-Keyless-Entry-37_W0QQitemZ300290481870QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item45eab51ece&_trksid=p3286.c0.m14&_trkparms=65%3A12%7C66%3A2%7C39%3A1%7C72%3A1205%7C240%3A1318%7C301%3A1%7C293%3A1%7C294%3A50

total costs = $28.98 shipping included. It takes me 1/2 hour to install it. I am very happy with it. You need to trick it to believe the door is open/close, as per my earlier post. Most system lock the car again if door is not opened within 30 seconds, it cannot be overrided.

bob_98sr5 · #27 06-03-2009, 01:10 AM

ah-kay,

very cool! thanks for posting that up. sure wish i talked to you first

sleek remotes, very trick.

re tapping from trunk lock, where exactly is it that youre tapping the wires? is it at the lock itself? and where are you tapping your constant and switched 12V? i did tapped at the ignition switch and the battery itself. long lines, but i know where those are

is there somewhere closer than that near the rear cabin or trunk?

ah-kay · #28 06-03-2009, 01:38 AM

bob_98sr5

Thanks for the compliment. It is few and far between here.

I actually do it in a much simple way. Mine is a 300SDL and the plug that goes into the trunk lock has 3 wires. 12v, 0 and a common. I cannot remember the color code but I can post again if I find out later.

1) I tap the 12v from the 12v plug wire.
2) Cut the common and connect the 2 ends to the keyless unit.
3) wire up the parking light to door trigger(+) or (-).
4) done
5) Tug everything in the trunk lock's void space.

I do not bother with the starter cutoff relay nor the shock sensor. I could wire up the parking lights but I hesitate to do it as I do not know how much current I can drain from the connector plug. One can run the parking light wire to a relay and have a separate 12V from the trunk lid light ( more current available for all the parking lights ), use the relay to control the parking lights. Do not do it as it is too much hassle for me.

scottmcphee · #29 06-03-2009, 03:10 PM

Don't make this hard.

Do it the easy way... Your trunk key will lock and unlock all the doors and trunk simultaneously, so dig out the harness going to the truck latch. I bought a $10 unit on ebay that came with 2 fobs (nice metal ones with lock and unlock symbols on two buttons). Mounted it on top of taillight inside the car with two-side sticky foam tape. The unit is about 2" x 3". Connected one output to one of these trunk latch wires, and the other output to another wire, even got constant +12 from that harness. Ground was easy to find in the area, and done. I did not bother re-connecting the harness to the trunk latch, because, I didn't believe this at first but it's true... once you have remote fob you'll never use a key in the trunk again, or in any door for that matter. Save your key for the ignition, that's the only place you'll need it. No wear and tear on the door locks which are famously difficult to change out...

The range I have is great, nearly 100' from the car. I like the nearly silent operation, with no flash or honk and any bull**** that advertises your car to a shopping mall crook who finds your set of keys left behind... and goes hunting.