Disable Central Locking System - PeachParts Mercedes-Benz Forum

77280E · #1 11-19-2003, 07:23 PM

I have a 1977 280E and would like to disable the (CLS) Central Locking system. Does anyone know the necessary steps to take to accomplish this?

Advice will be greatly appreciated!

Thanks!!

DREYTAY · #2 03-26-2007, 12:32 PM

Hello my name is Drey and I owned the same model as you, this isn't a answer to your question, but I was hoping we could share ideas.

Thanks

nhdoc · #3 03-26-2007, 07:22 PM

These systems are vacuum powered. You need to find the vacuum line under the hood which is the main feed line. In most cars the vacuum hoses will be up against the firewall.

You'll need to find the line which comes from the intake manifold (source) and goes through the firewall to feed the vacuum reservoir. I think it will go through the firewall near the brake booster. There will be a checkvalve in the line to prevent the vacuum from leaking back once it is built up in the reservoir.

Once you find the right vacuum line you can simply disconnect it from the manifold and plug it at the manifold point and at the line so if you (or some future owner) want to restore it you can easily do so.

This will disconnect not only the locks but the trunk lock override and the fuel door lock too. The fuel door will fail safe unlocked - not sure about what the trunk lock will do but in any event you will be able to open it with the key.

Personally, I really like the central locking system and don't know why you'd want to disconnect it but that's how to do it.

Tomguy · #4 03-26-2007, 08:49 PM

Tip: The easiest way to disable the system is to reverse the check valve.

nhdoc · #5 03-27-2007, 07:36 AM

Quote:

Originally Posted by Tomguy

Tip: The easiest way to disable the system is to reverse the check valve.

That IS clever!

300SDog · #6 03-27-2007, 01:30 PM

Still you will want to pull door panels and disconnect the diaphrams, then all locks will work smoothly in manual mode.

Mike F · #7 04-17-2007, 03:08 PM

Hi there,

I just got a '78 350SE and I would like to plug an alarm in. Does anyone know if the door lock has an electrical switch that I can connect to to activate the central locking? I'd like the alarm to open the locks if at all possible.

I also want to install cruise control, any tips?

Many thanks,

M

250 Coupe · #8 04-17-2007, 04:32 PM

If it's a W116, it's engine supplied vacuum only for the door locks. Other cars have a pump under the rear seat but I don't know what triggers it.

I'm about to order a kit from A1 Electric to convert my 450SEL to remote electric door locks as I've a bunch of leaks and some broken hard lines.

Michael

Mike F · #9 04-17-2007, 09:00 PM

Thanks a million Michael (great name you have there),

Have a look at 12voltshop.com aswell as A1. I bought stuff from them before and I would describe it as cheap and looks cheap but functional.

The engine supplied vacuum is a mystery to me but I understand that it comes from the carb. I know that I could stick solenoids into the doors but if at all possible I would really like to keep the 29 year old car almost original. In a lot of Mercs the front door locks have an electrical contact that can be used for central locking and also for total closure if interfaced correctly. If the 116 has electrical contacts I would like to interface to them, if it has some kind of vacuum valve, I am interested in interfacing with it.

But when the old system just doesn't have a modern equivalent I will just add it. Rain sensitive wipers, L.E.D. brake / stop lights and cruise control are on my list right now.

I don't feel like fitting the A1 kit, it might be cheaper and easier for you to fix the vacuum fault and interface to the O.E.M. system than buy the kit and stick it to the car (4 doors, 1 gas tank and a trunk = 6 actuators), you'll have to open the car up to the same extent. But if you don't want the trouble I understand, anything that makes your car do exactly what you want to do and the way you want it done is a good thing.

Thanks for the help, I appreciate it,

Michael

250 Coupe · #10 04-17-2007, 10:25 PM

I dropped $225 at A1 for six actuators and all the electricals needed to hook it up, including keyless entry and an alarm I may never actually use. The stuff at 12volt.com looks the same but if I'm going to the trouble of changing everything, I'd rather get top shelf stuff and not have to mess around.

The valve in the drivers door looks like this, shouldn't be too hard to hook up a single two wire actuator in place of the vacuum unit in the drivers door and stiil leave everything else vacuum.

Michael

250 Coupe · #11 04-17-2007, 10:26 PM

By the way, Michael is my favorite name

Michael

Mike F · #12 04-17-2007, 11:06 PM

Drat,
That thing looks like a bicycle lock. That's a lot of sucked air to get around. It sounds to me like you got a good deal.

Thanks for the pointer to A1, looks like much better quality than 12volt (and great stuff for home automation aswell).

Where did you get the pic of the valve? I use alldatadiy.com for my w140s and I have had the pleasure of working NEAR the good people at Temic and later Continental Temic in Friedrichshafen in Germany so there was always a brain to pick / a HTT to 'field test'.

I think I'm going to have to learn a lot about vacuum systems but it seems to fit in with the cruise control effort. It costs nearly 600 US for an aftermarket retrofit kit with memories which to me seems a high percentage of the price of the car.

Thanks again and I stand informed and educated, thanks,

Michael

250 Coupe · #13 04-18-2007, 12:15 AM

Click the "Buy Parts" link at the top of this page and select the year and model for your car. Find the part and click the little picture to get the big one. Right click and select copy image location. When composing your message click the "insert image" icon and paste your link.

The CD-ROM for the w116 chassis is online at www.w116.org.

$600 seems very steep for cruise control, JC Whitney has them for much less but shipping overseas may be an issue.

Michael