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Old Jan 31, 2012 | 01:39 PM
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latemodel21
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Joined: Apr 2011
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From: Gilroy, California
Default Re: All about Mercedes Steering Wheel

Hey Eddy,

Let me add a little info on paddles and steering controls.

To begin with, crossfires and R170 slk's do not have any provisions in the clockspring assy (this is the device that passes electrical signals from the turning steering wheel to the non-turning steering column/car) for more than 4 wires. 2 of these wires are used by the airbag squib and the other 2 are used for the horn.

Newer Mercedes models (that have more controls on the steering wheel) have added wires in the clockspring for additional controls (which are "voltage coded" in the wheel before passing thru the clockspring and then put on to the CAN bus (in the jacket tube module)). They also have additional wires available for circuits that are not "voltage coded" such as steering wheel heater and paddle shifters (paddle shifters are then added to the CAN bus in some models). Many of these features and functions rely on modules in the steering wheel to voltage-code the signals and ALL OF THEM require ADDITIONAL wires in the closckspring.

I offer the previous paragraph so that you understand what Mercedes has added to use more steering wheel functions.

The dilemma is the limited number of wires (circuits) available in the crossfire steering wheel (because of the clockspring only having 4 wires). Jimmy got around this by adding a remote transmitter and receiver that seemed to work fine (although, he is now getting around to installing one of my kits). I got around it by creating a module (placed in the wheel) to voltage-code the horn and paddles, feed the signal through the clockspring on the horn-signal wire and then finally decode and execute using another module mounted closer to the shifter...


Back to more current Mercedes wheels. You probably noticed that Jimmy started with a wheel that had many controls but blanked them out (as they would be unsupported/unusable .... in the crossfire). This will be the case in any crossfire.

As far a paddle-equipped Mercedes wheels .... most (all?) wheels that come with paddles also have other function buttons (that will be unsupported in the crossfire) .... additionally early Mercedes paddle shifter setups used a curious scheme where the "down" (left) paddle was a "normally open" style switch (with a zener diode in parallel with it) and the "up" (right) paddle was "normally closed" style switch (with resistor in series with it). This combination of two switch styles was employed on various models and needs to be avoided (I have created a work-around for these, but that is to install new paddles on cars that were designed to use that style). later AMG vehicles (2007 and later?) used the newer style paddles (like i recommend for the Kit) these switches are both "normally open" style switches. These later paddles are high quality and inexpensive.

Sorry if this is too long, but the answer I gave you last night (in the paddle thread) was too short and I wanted to add some detail.

My $.02 .... I would see how reasonably priced you could get a crossfire wheel redone (with cool grips and reliefs for paddles) or install the paddles in the crossfire wheel as it sits (many are very happy with that).

However, I really would love to hear about the discoveries others have made relative to finding other Mercedes wheels that fit the crossfire

A Mercedes wheel that fits nicely would be/is cool .... but you are probably going to want to start with a non-paddle one (so you don't end up with unused buttons)

Chris
 

Last edited by latemodel21; Jan 31, 2012 at 01:45 PM.
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