Big Dog, very interesting.
Mine is a '91 S-class, so should be similar.
What do you mean by Red sensor on the key: RF ID? coded resistor?
My keys appear to have no RF or resistor chips, or any embedded electronics.
But I guess it could be hidden under the rubber end.
I assumed it had no such system.
I'll try the push-button right-hand locking and see if it triggers the alarm.

This is getting interesting; makes me want to pull the door lock and see what-all they have in there. I know it's not too simple, because if you try to push the driver lock down, with the door open, it won't go down - so it's pretty smart.

DG

I always thought that the keys with the red dot on them were simply the master keys for the car, and had no other special significance.

However, none of my original W124 keys had the red dot on them and when I ordered a new set of locks and keys, none of the new keys had a red dot on them either.

Keyless Entry System - 1989 300E!
 

Here is a picture from page 30 of my owner's manual which is self-emplanatory. I have two keys and both have the RED sensor on it.

Picture quality not the best. Second paragraph reads: Vehicles equipped with the anti-theft alarm system are identified by having a red dot on the master, valet and flat keys.

Hope this helps!

So the red dot is just an identifier for car with alarm, not anything more.

I have three new keys for my W124, and two old ones - none of them have ever had a red dot on them, and my car has an alarm.

Those relays look like VW headlight relays - look for headlight relays at any accessory/car parts store.

Guys, I installed the $45 universal Mercedes eBay unit on my '91 W126 today.
In a netshell: it worked like a dream the first try!!!!!!!!!

No additional relays to buy, no additional alarm wiring, just the 4-wire hookup at the pump wires like Costanza did; plus one violet wire over to the rear parking light conector. Bam, done!

Locks work, alarm arms and disarms properly, and the parking lights flash once to lock, twice to unlock.

This is too good to be true!

A few comments:

- I have a '91 300SE, which has the driver door vacuum switch, but does not have the "convenience module" mentioned in some of the earlier install articles.
- I Hooked it up to the blue (passenger door) wire at the pump, and got the power/gnd from the rd/wht and the brown wires on the pump (just like Costanza's 4-wire diagram on this thread).
- I did have to tie some wires from the unit together, but the instructions were clear enough on this.
- I tied the the violet park light wire directly to pin 6 on the left taillight.

I tried various tests with the alarm, locking and unlocking with both the remote and the key. It seems any combination of locking/unlocking using the remote or the key will properly arm/disarm the alarm. Cool!

Only issue I had was when I was testing various sequences of remote/key/alarm trigger. Sometimes the remote would lose its sequence if the key was used or the alarm was triggered. In that case you sometimes had to cycle the remote button through one lock/unlock cycle so it could relearn.Then it worked fine again, and would even kill a beeping alarm.

So, I would call this one a 110% success.


DG

Good luck!

You have much more patience than many others including myself! I could say with much assurance that my results would not have come out as well as yours.

Yes.
I had the weird, " losing its place" issue on my 2.3-16v 190e also. SOmetimes if you would use a key or combination of unlocking manually and with the key the system would lose its place and try to lock the car when it was already locked or unlock when unlocked. In any case a second attempt would allow the system to realize where it was and work correctly. AND. If this is the only issue with being able to unlock my dorrs without a key fromnow on, I can totally accept it.
It works great is I just dont mess with it. Unlock and lock with key fob and it works correctly every time.

Yeah, Chris, that little confusion by the remote won't EVER happen, unless the car is broken into, or the keyfob battery dies and we have to use the key - so no biggie at all.

One of the guys on this thread (or another) had trouble with his system just clicking and not opening the doors. When the remote is confused that's exactly what happens if you don't go thru a lock/unlock button-push cycle.

I'm so excited - I still have a pink wire that can fire something else; think I might install a little soft beeper to go with the blinking lights.

DG

Mine was a REC-11 from Omega, but basically the same as what you used to do the job. It came with a piezo buzzer to provide audible feedback when operating buttons and programing but it is very very quiet. I think I will use a 30 amp relay and the piezo trigger wire to operate the car's horn instead of the buzzer so I can hear that it received the button input. Also, I have a pink wire 3rd channel that I dont have a use for, a trunk unlock/popper is useless with the MB trunk lock and opening mechanism. Closing of opening a window or the sunroof just sounds like a wiring nightmare and asking for trouble and I cant think of any other uses for it. Any ideas?

My new Caddy Wagon remote start turns on the seat heaters while I'm having coffee, still in the house. Now that is technology at its best. That would be a wiring nitemare (since I don't have seat heaters in the old Benz).
One thing I won't try is tying that pink wire to the alarm horn (to beep when locking/unlocking). After all the alarm issues from the guys here, I'm gonna leave it alone.

DG

I took no chances on the install and isolated every wiring splice into the OEM harness with diodes, big ones, like 6 amp diodes. Nothing can feed back to the alarm or vice versa. I will be sure to continue the good practice when I tie into either the horn or alarm horn, or amybe just an add on horn to be safe, but any way, always isolate with diodes as to not feed back juice to the car's harness and cause bad things to happen at the very least.
Relays and diodes are your best friends when adding electronics to your car.

Do you add the diode in series ? How about some diagrams to enlighten us all.

I suck at making diagrams on the computer, I'll work on it...Yes, in series. Typically you want to use a good diode anytime you splice power to another OEM power wire, otherwise, you can get a feed back of electricity when the factory wire is energized, anything like lighting, relays, horns, antennas, windows, etc all should be used with a diode. I'll TRY to do some diagrams.

DG/Chris,
What are the exact model Keyless system did you purchase?

You said the lights flash when locking & unlocking. Does the dome light illuminate like when using the key? Do you have a confirmation auditable churp?

On your units, do they have a Remote Panic Mode? How is the Panic mode activated/deactivated?

And finally, for the windows & sunroof. Does the windows rollup/down OR sunroof open/close with the remote (like with the key)?

Scotty,
I used a REC-11 from Omega. Many different ones out there and they are all about the same. Window and sunroof operation is much much more involved and not a direct setup on any unit i know of.
Panic is a simple 4th channel on the remote and is easy, push and hold to set off, push again to stop.
You can set most up to include turning on the interior lighting when you lock and unlock, I did to mine. It also flashed headlamps and the horn honks as a signal that it unlock./locked.
It did have a third channel, but I had nothing left to use it for, sunroof was very involved and I could only make it do one window easily and it is hard to wire to make it do the window up and down so only one way is easy, I decided to leave it alone. No need for a trunk pop since the car has a deck spoiler and is heavy to pop and auto unlocks with the doors.
Chris
Good luck.

Thanks Chris,
I just purchased the Omega REC-11 as well. Planning to install next weekend with information found here. Im currently trying to determine if I will need relays for my 95 C280.

How many diodes did you use? At this point, Im only planning to use 2: one for the Omega power wire & one for the blue drivers door wires. But where/how do you connect the unit to the Horn, headlights and interior lights? Im thinking of using the emergency flashers instead of headlights but must find a connection point.

Please explain how to wire up the diodes and the diode size required. Dont know anything about diodes. How many volts (12v?) and how many amps?
Where to purchase them? Radio shack?

This is sooo cool... Ive been wanting to install a remote for years on this car..

Go to Radio Shack and buy 6amp diodes, they are larger than a typical diode but look the same, black with a silver or grey stripe. Power will flow towards the stripe and not the other way around. You will need a 30amp relay to use the horn, the trigger wire to the horn is not enough to set it off properly, use the trigger wire to activate the relay and a 12v continuous source for the horn power from the relay.
The door lock trigger does not need a relay and neither does the interior lighting trigger. I did use a relay for the headlamps and I pulled the power from the output to the lights at the headlight switch, an easy place to use and work from.
PS - Change your interiro dome lights out with hi power LED festoon bulbs from www.ledlight.com and you will like them a lot more, no heat issues, and a super white/blue tint to the light like the brand new MB cars. Plus, a lot more light output. About $14 each but worth every penny.

LED Falson Bulbs - Great Idea!!

What size do we need? My bulbs is like 1 1/2"
They now sell two types: One filament and Two filament.
Also 2 brightness: Super White (5500K) and Hi power.

Which one did you freaking order??
Wayyy too many choices... lol

yes, way too many choices and I did a trial and error with my 2.3-16v and it got expensive but I finally found the perfect bulbs.
I think your bulbs are like a 38 or 42 mm bulb.
Go to one of these web pages... The second one is the better bulb, 6 leds and very bright, but web site is harder to navigate.


http://www.ledlight.com/detail.aspx?ID=279

$9.00 plus s/h for 4 LEDs

or go here and get these

www.superbrightleds.com


Select Bulb Length
WHPx42mm 4210-WHPx

Select Number of LEDs
6 LEDs (+ $7.00)

High Power LED Festoon bulb
Festoon bulbs with 3 or 6 High Power Cool White LEDs, 12 VDC
42mm lengths
$ 7.95 + 7.00 = $14.95 plus s/h for 6 leds

Those are very expensive. Purchased items from superbrightleds before and had a bad experience with non-working new bulbs but their exchange policy sucks..

I usually buy all my LEDs from this guy in Hong Kong: http://stores.ebay.com/warden-jp2002
JP usually has everything in-stock, new LEDs shows on his site 3-6 months before on US sites, shipment takes 7-10 days normally, replacement policy is good, and he is much cheaper for the LEDs & shipping..

JP also sells a set of LEDs for all the exterior lights for our cars. I think you must email him for the pricing information.

Check him out.. You wont be disappointed..

I sent you a PM... Please respond..

Wiring Locations??
 

Okay... Back on topic..

The thread outlines the main connections for the unit but not the connections for other devices used.
Where are at OEM connection wires for the other connections??

1. Horn connection - Where is the positive wire connection location for the Horn?

2. Interior Lighting connection - Where is the interior light connection location?
** Note: My interior lights comes on and stays on for 10-15 sec using the key after unlock. Is this a necessary connection?

3. Headlamps - Which wire at the headlamp switch is the output wire?

4. Parking lights - Thinking of using parking lights instead of headlamps.
Which wire is used for the parking light connection?

Scotty, sorry for late reply, flu bug.
I used the Stealmycar unit on ebay that was advertised specifically for MB.
At the time they had one specifically for the 126 for $50, and a generic MB
one for $45. I bought the generic and it was fine.
It only has two buttons on the remotes; no panic button.
It unlocks and locks, and I don't "think" it turns on the interior lights, I haven't noticed.
It has 4 relays inside, so no extra relays required to lock/unlock or flash park lights. It had a specific wire to flash the park lights, and it hooked right up to the left taillight. No beeper, but I plan to wire one into the light flasher, so it beeps when the lights flash. There was another pink wire for trunk release, etc; but I cannot see any voltage on it when the unit fires.
see my indstall comments abover, piece of cake, working great; but I do need a beeper or horn relay, can't really see the parking lights flash on a bright day.

DG

Scotty, I can only answer question #4 above; park lights.
I tied directly into the left taillight/parking light connector. pin #6, with the gray/black wire. I just popped the cover off the 8-pin connector and soldered the wire directly to the pin. This flashes all four parking lights when I trigger the remote. (old '91 126 model).

Yeah, I would like to know the location of the horn relay on the 126, I plan to tie into that also for the beep.

DG

Thats cool DG.. Flu bug sucks. Hope you feel better soon..

Purchased the Omega unit like Chris.. And bought diodes & relays today.. And preparing to install on Saturday.. My questions were about installing convenience features, as the lock/unlock remote installation instructions are documented well in this thread...

Your response lets me know that parking light connection is possible at the tail lamp (doing a trunk install). I do have wiring diagrams but Im not sure which wires to tap into: Positive OR Negative wire, relay wire or trigger wire. I want figure the wiring out before I start. Hopefully, I can finish this on Sat..

Heres some horn connection info: http://www.the12volt.com/carsecurity/page3.asp#hn
And heres the wiring diagrams site for a 91 300SE (site appears to be up only during the day):
http://www.autolib.diakom.ru/CAR/Mercedes-Benz/1991/300SE/SYSTEM%20WIRING%20DIAGRAMS/

Ive been reading up on installing diodes. Now, Im more confused.. We need a diode writeup for our cars..
The diode will stop leakage and I understand how. But you install it depending on the flow of current + & -...
Well for our door locks, the single line trigger is both positive & negative depending on the lock position.. Thus, my confusion..

Hmmm, interesting about the door wire diode. Yeah, current needs to run both ways to/from the motor on the green wire; so maybe cannot diode it - I didn't. Maybe Chris can add some inputs.
But since this door-lock wire is pretty isolated to just the door switch and the vacuum motor, probably no issues with other systems; and if the keyless unit blew it would either put 12V, ground, or nothing on the green wire, all of which it sees in normal operation. so probably no harm done to the car's system. I did diode the light wiring, just put it inline in the wire between the keyless unit and the light wire connector pin #6. allow 12V current flow FROM the keyless unit, but not back to it.

Can't help you on the Omega hookup for the lights. My unit had an internal relay that supplied a 12V flash to the violet wire, and hooked right up to the park light wire. Gnd was obtained thru the Keyless unit ground wire at the vacuum motor. With the omega, I assume you have a wire that provides a 12V flash, but it may need a relay to supply enough current to flash all 4 park lights. If so, just a std relay hookup should work - hook the Omega signal to the trigger, tie in a hot 12v and gnd, and hook the 12v output to the park light wire.

DG

I only used diodes on the horn ( for confimation beeps), the interior light on when unlock, and the parking light flash. No diode on the door lock, I believe it is internal to the unit.

I used the standard relay hook up that s guru mentioned to use the horn and lights. Use the units wires as the trigger for the relay and use the constant power and the terminal block in the drivers side foot well for the 12v supply. There should be a terminal block in the far back corner of the driver's foot well outboard side, that has connections avail for both ingition on 12v and constant 12, a great place to pull power from. Mine are even marked as yellow and red connections ( 190E)

Chris

Thanks Guru & Chris.. I have mapped all known connections and have located
the wires in the car. Only decision remaining is the actual install location:
Under the Dash OR In the Trunk. Trunk has parking light and vacuum unit;
but the dash has all of the other connections. I will probably do a dash/Under seat
install and connect the parking light flash to the emergency flashers using a relay.

Im all set-to-go here now!! Hopefully, my Omega unit was delivered today..
Will check my C280 for a footwell terminal block tonight. Hopefully, I also have a
ignition 12v and a constant 12v like in your car..

Reading the User Omega Manual, I found all of the default settings. It defaults to
"Doors Lock With Ignition ON". How? Does this unit have a connection wire for the Ignition too?

BTW, did you guys see my links above for the LED and wiring diagrams.

The unit is just recognizing the power on with ignition and locking your doors for you, it drove me crazy, I turned it off.

Kewl,
I will turn off mine too. I would like for it to lock automatically only when put in Drive...

My ebay unit still hasnt arrived.. Thus, all of this preparation and no freaking unit... Im sooo pissed....

Yes, if it was like the wife's car and would lock and unlock as you went in and out of drive it would be worth it, but since there is not a clear way to set it up to do that I dont really want it locking every time I start turn the key to the "on" position
Not sure if there is anything we could use as a trigger to make that happen.
Maybe something with the starter interupt when it is in drive or reverse might work...
Sorry your unit didnt show yet.
Everything happens for a reason...we just dont always know what that reason is.

Im actually thinking of a connection from the Neutral Safety Switch, where a Lock trigger signal is sent for the Drive position. The Neutral Safety Switch should be able to send a signal for the Drive position and connect this to the Omega ignition signal wire. Reverse & Drive would send a double signal when putting in gear which would defeat the purpose here (reverse-neutral-drive gearshift positions = lock-no action-unlock).

Im also thinking of my wife for this setup. It would be a single trigger to lock when the gearshift is in drive position (unless its already locked). Pulling the Drivers handle will automatically Unlock all doors. For wife safety, only unlock when a purpose event happens (already provided by OEM system).

Omega default settings would be:
Doors Lock With Ignition "On" : Default ON
Ignition "Off" Unlock 1 & 2: Default OFF
Connect the Omega Ignition wire to a signal wire from the Neutral Safety Switch

Now, does the Neutral Safety Switch actually send useful electronic signals??

The Neutral Safety Switch wont work!!

Tested it for a signal and it only controls starter activity signals much like the ignition switch.. Just an earlier and much shorter signal...
I will just not use the Automated Lock/Unlock features... Unless someone here has other ideas!!

C280 Wireless Install
 

Finally, Installed my Omega REC-11+ unit and a siren.

BTW, the 95 C280 OEM locking system is actually a 3-wire system. Both front doors use the same 3 wires and the signal is not on a single wire.
There is a Lock, Unlock and Ground wire that controls the locks. This actually makes the install easier.

The overall install was relatively easy. The hardest and time consuming part was finding the C280 connection wires. Installed the unit under the dash.

But here's the 95 C280 connections found on my car (as yours may be different):

----Kit Wire--------------------C280 Location-------------
1. 12 VOLT Constant.............Red Wire – Power Block (under gas pedal)
2. Chassis Ground.................Brown Ground – Left Floor Wire Panel
3. Ignition...........................Violet/Blue - Steering column (used diode)
4. Trunk Release .................NOT USED (requires a trunk release popper)
5. Starter Interrupt .............NOT USED (OEM Alarm Starter Kill relay installed)
6. Headlights.......................Gray/Red (+), Headlamp switch (used relay & diode)
7. Parking Lights..................Gray (+) & Gray/White (+), Headlamp switch (used 2 diodes)
8. Dome Light Output............Front Door Pin Switch - Brown/Gray (-), Left Floor Wire Panel (used diode)
....................................... Rear Door Pin Switch - Brown/Gray/Yellow (-), Left Floor Wire Panel (used diode)
9. Power Lock Pulse..............Black (-), Left Floor Wire Panel
10. Power Unlock Pulse #1.....Blue wire(-), Left Floor Wire Panel
11. Siren............................Cut the Piezo wire (+) to Siren (+) wire (using relay)
12. Signal Antenna Wire........Installed under the Weatherstrip of the Front Drivers Pillar, held in-place with RTV

Hopefully, this will help someone else doing this!
Everything works: Headlamp/Parking Lights flash, Lock/Unlock, Panic, Dome lights & Siren churp.
Now that Ive found the Door Pin Switch wires, Im thinking of installing another set of relays/diodes to "Keep the Radio ON until Door Opens" mod.

KEYLESS ENTRY IS GREAT ! ! ! :D

Good job.
I still haven't found a suitable chirping horn for mine, but it's still on my list, and I have the wiring all hooked up. (maybe right after the water pump that is oozing).

DG

Thanks. The siren only chirps when unlocking & locking. Otherwise its quiet (even in panic mode). But it is better than the peizo which cannot be heard 5 feet from the car.

I also took the advice from Chris. Replaced the dome lights, reading lamp, and trunk lights with LEDs ! ! They look great and Zenon White is very bright. These were cheaper prices and shipping (about $30):
Dome & Trunk Lamps (4): http://cgi.ebay.com/ebaymotors/1pc-42mm-211-212-214-HP-LED-Xenon-White-Festoon-Bulb_W0QQcmdZViewItemQQ_trksidZp1713Q2em153Q2el1262QQcategoryZ33713QQihZ011QQitemZ320223124451QQtcZp hoto
Reading Lamp (this actually fits): http://cgi.ebay.com/ebaymotors/2pcs-168-194-Refractor-5-Power-LED-White-Wedge-Bulbs_W0QQcmdZViewItemQQ_trksidZp1713Q2em153Q2el1262QQcategoryZ33713QQihZ011QQitemZ320223124346QQtcZ photo
The LEDs took about a week to arrive from Hong Kong.

The relays are wired up for the "Radio ON til Door Open" mod. Planning to install next weekend. After over 12 years, this car is finally getting some actual creature comforts. :D

AT long last, I have finally attempted at hooking up an Omega REC-11+ with the relay set up shown here (yes I wired two relays together ). Anyway, I hooked it up to the vacuum pump connectors on my 1987 260E and it kinda work.

I press the lock button on the remote and sure enough, the locks moves down on all four door and the trunk. However about 1 second after it moves down, it pops right back up into the unlock position.

What could I be doing wrong??? Thx in advance.

The lock signal needs to be present for about 1 second or maybe a bit longer for some vehicles. If the omega unit you are using can be programmed, try setting the lock pulse time to about 1.5 seconds.......

J. M. van Swaay

Just looked more closely at the schematic you provided--I see you already have a 2 second pulse. Is there continuity between relay contacts 87a and 30 when the relays are not energized? (can you still operate the locking system with the key in the front left door? if so, you have continuity between these contacts)

J. M. van Swaay

Well this unit can be programmed for either 0.8second or 3second. So I current had it set for 3 second.

I hooked up my multimeter in continuity test mode and it shows continuity from 30 to 87a (on both relay). I didn't check to see if the key still works in the front lock. But according to the circuit shown it should still works because when the relays are not energized current should flow through the blue pump wire as before.

I'm not sure I can be of any more help.

One thing you might try is to manually activate the lock relay by grounding pin 86. Leave the ground on for several seconds. (maybe 5 or 6) If you have a successful lock, then you will know that your omega provided lock pulse is not long enough. I'll have to look at the lock logic description on the MB service CD--it might be possible that if you have a leaky or slow system, 3 seconds may not be long enough.

Disclaimer: I ususally don't post unless I'm pretty sure about the issue at hand. In your case I'm not sure I have a good understanding of what your problem might be. The above suggestion is just a trouble shooting guess.....

J. M. van Swaay

IMHO, I think you may have selected another alarm setting incorrectly. IIRC, there is a remote double-pulse feature (sends 2 pulses from the remote); make sure its set to off.

Otherwise, I would first test with the key to make sure the locks. This may help isolate your problem. If the locks still works normally, I would set the signal to the shorter length and retest (will require you to be closer to car for activation). If using the key dont work, then you definately have a wiring problem somewhere (probably in the relay setup).

Note: I had voltage leakage from the alarm system causing strange things to happen. I installed diodes @ all power & device activation connections (see post #135) to counteract this and everything then worked as designed. Just another suggestion.

Hopefully, you find your little electrical gremlin... Good luck!