KEYLESS QUESTION - PeachParts Mercedes-Benz Forum

Basstrip · #1 11-24-2009, 07:08 AM

I have a 300SD 92 W140 I would like to install a keyless system, since all I have is a key blade. I don't need in alarm, but I would like the unit to operate the roll-up windows when locking the doors. Has any body install inexpensive system to this type of model?.

mbdoc · #2 11-24-2009, 10:03 AM

If you order a new remote key from dealer the car is already to do that.

Basstrip · #3 11-24-2009, 01:07 PM

Yea, I call two dealers, they charge $249.00 per remote. That's way to much.

Jeremy5848 · #4 11-24-2009, 01:15 PM

Then you're stuck. Options: join MBCA, get ~15% discount at dealer (save $37.50 on $250 purchase, pays for most of membership fee). Second option, ask Phil at FastLane (click Buy Parts at top of page) to get remote for you, may be aa much as 10% discount over dealer retail. Third option: do without.

Basstrip · #5 11-24-2009, 01:50 PM

I call both sponsors. They do not deal with alarms or remote replacement. One of them suggested to ask on the forums, what people done in the pass.

Matt L · #6 11-24-2009, 02:18 PM

$300 for the key, but how much for the aftermarket alarm? Say it's $150. Hacking up your car's wiring to save $150 is false economy.

Phil · #7 11-24-2009, 02:20 PM

You might try calling this place or some one like this that carries aftermarket remotes.
http://www.originalkeyless.com/main.sc
You also might look at the systems these guys have.
http://www.bulldogsecurity.com/
I bought a remote door lock system from them but they also seem to have a lot of other stuff.

Graplr · #8 11-24-2009, 03:09 PM

Quote:

Originally Posted by Matt L

$300 for the key, but how much for the aftermarket alarm? Say it's $150. Hacking up your car's wiring to save $150 is false economy.

Agreed. Either do without or get the factory one. You won't save much money getting an aftermarket. Then you have to mess with the install.

Jeremy5848 · #9 11-24-2009, 09:07 PM

If you use the blade key in the lock and keep it turned to the "lock" position, the window close feature should activate after a few seconds, no? I thought that was how it was designed to work. My '96 E300D (W210, OM606NA) does that and it should be very similar, electronically, to your 140.

If yours is supposed to have that feature but it doesn't work, then you may have a faulty "convenience module." The 140 should have at least two -- one that allows you to adjust the seats when either front door is open and one that allows the key or remote to close all the windows and the sunroof. They are expensive goodies -- junkyard your best bet if yours is indeed bad.

As an alternative, you should be able to buy an inexpensive keyless lock system for about $30 and wire one of the outputs to the "convenience module." This would require schematics for your car and some knowledge of electronics so you don't do more harm than good. The 140 is a complicated beast and I would want to know what I was doing before I tackled this project.

When I installed a keyless lock in my '87 300 D Turbo (W124, OM603), I wired one of the extra outputs via a relay so I could close the sunroof with the remote. I could have done the same for the windows but it would have meant another relay and a lot more wiring and I didn't see the need.

Jeremy

Basstrip · #10 11-25-2009, 02:51 PM

System work fine with the key blade. All want is a keyless remote for convenience.

Jeremy5848 · #11 11-25-2009, 04:06 PM

Then buy an inexpensive keyless remote lock system w/o alarm (eBay, $30) and wire it to the convenience module to close the windows.

Basstrip · #12 11-25-2009, 10:39 PM

That's it!!!!!. Now what would I look for. What I mean is, is the system has to be a particular type to fit the convenience module?

scottmcphee · #13 11-26-2009, 12:16 AM

I discussed the answer and how-to in this thread:

92 300E Key Issues

Tell me this, does the roll-up with key feature also work from the trunk in your car, or just the doors? (Both doors, or just the driver's?) I have to ask, because for 1987's we didn't get the feature.

Jeremy5848 · #14 11-26-2009, 02:23 AM

Quote:

Originally Posted by Basstrip

That's it!!!!!. Now what would I look for. What I mean is, is the system has to be a particular type to fit the convenience module?

No, but you'll need to know how the convenience module is wired and where it is located. You'll probably want to add a relay to the keyless remote kit so it can duplicate the switch closure that the key lock does.

If you can't get information on the convenience module, you can remove the driver's door skin and look at the switch on the lock assembly. If the trunk lock in a 140 also has the ability to close the windows then Scott's idea is better, the trunk lock is a lot easier to get at. With access to the switch, you don't need to know where the convenience module is or how it's wired.

I don't know how long you have to keep the key turned over to "lock," probably 3-4 seconds? to get the windows to roll up. The keyless remote will have to maintain a closed relay contact for at least that long. You'll want to get a kit that allows you to keep the remote button pressed until the windows roll up. Some very basic kits won't do that, all they do is lock and unlock; you'll need an "advanced" kit with optional buttons.

scottmcphee · #15 11-26-2009, 03:01 PM

What I'm getting at is, if you can use the trunk key to also do roll-up, then just get the "momentary" type remote kit, its relay stays latched for as long as you hold the remote button. You get to time how much action you want, a brief press, locks, a longer hold, windows.

I have been making and selling window rollup kits for years, you can see them at www.autowindow.com