Keyless Entry Installation

Instructions for installing the I.C.Dynamics Valiant 2RTA keyless entry 

1985 Mercedes 500SEC

(These instructions probably will work for all Mercedes, as the locks are all similar.)

I bought my unit from JCWhitney. Here is a link:   http://www.jcwhitney.com/product.jhtml?CATID=4703

Overview:

Advantages:

• The Valiant uses 64-bit messages and code hopping techniques. This makes it very secure.
• Easy to install
• Low cost
• Small keyfob control

Disadvantages:

• The Valiant will not work with the Mercedes lock system right out of the box. You must modify the printed circuit board by cutting one trace and placing three jumpers.
• This installation is not hooked to the horn or to the car lights. There is no feedback to tell if you've locked/unlocked the car except the door buttons moving and the "click" from the gas filler door locking.

Quirks:

• If you've installed the keyless entry control on the trunk (boot) lock, and you lock the trunk by withdrawing the key in the "secure" 3 o'clock position, the keyless entry is disabled.
• If your car has the built-in alarm system, you must install the control unit on the trunk lock. Otherwise the alarm will go off whenever the car is armed and you unlock it with the keyless system!
  

Tools needed:

• Pencil-type soldering iron and rosen-core solder
• Small, sharp knife
  
• #1 Phillips screwdriver
• Small drill
• Terminal crimper
  
• Normal tools to remove trim to get to the door (trunk) lock.

Materials needed:

• I.C.Dynamics Valiant 2RTA keyless entry system
• Sheet metal screws to secure the Valiant module to the car
• RTV
• About 20 cable ties
• 2 splicing terminals
• 2 in-line terminals
  

Alarm Schematic:

Procedure:

1. Remove case from Valiant module. Make the modifications as shown below on the reverse side of the PCB. An easy method of cutting the trace is to make two scores across the trace about 1/8" apart with a knife. Then heat the section of the trace between the scores with your soldering iron. Rub while heating and you'll find the section will come right off.

2. Re-assemble the Valiant module. Make sure to route the antenna wire out between the blue (unused) connector and the 10-pin main connector.

3. Find the harness that came with the Valiant. It has 10 wires inserted into a plastic Molex connector housing. Remove all wires except for 4: Red, Black, Gray and Yellow. Use a small screwdriver to press the exposed contact tab through the hole in the side of the plasic connector housing while at the same time pulling on the wire. The wire and contact will slide right out.
   

4. I used the pneumatic lock module next to the trunk lock. Any lock module will work (see Quirks above). I chose the trunk module so the Valiant's antenna could be placed in the tail light assembly. Because the tail light is plastic, this is like placing the antenna on the outside of the car. The four wires from the Valiant module connect directly to the lock harness - there are no other wires to connect.

5. Decide on where you want to mount the Valiant module in your car. Check out the harness routing to be sure you have enough wire. You will cut and connect the Valiant's harness in the next step, so make sure everything fits. The picture below show how I did it. There is an existing grommet next to the tail light where I could run the Valiant's harness from the lock assembly to the tail light cover.

6. There are three wires in the Mercedes harness that connects to the trunk pneumatic lock module: Brown (ground), Red/Black (+12 V), and Yellow (control). Cut the yellow wire, leaving enough sticking out of the connector to make a connection to the Valiant harness. If you use a lock module located in another place, the wire colors may be different.

• Splice the Black wire from the Valiant to the Brown wire in the lock harness. I used some neat 3M splicing terminals I found at the auto supply store. This is the ground connection.

• Splice the Red wire from Valiant to the Red/Black wire in the lock harness. I used the same type of 3M terminal. This is the power wire tothe Valiant - it has an in-line fuse.

• Connect the Gray wire from the Valiant to the Yellow wire sticking out of the lock connector. The Gray wire connects to the lock assembly.

• Connect the Yellow wire from the Valiant to the Yellow wire in the car's lock harness. The Yellow wire connects to the car's harness.

7. That's all there is to it. Put eveything back together. Enjoy!

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