Hi all -

Does anyone have a detailed wiring diagram for the radio controls on the steering wheel? Ideally it would be the voltages expected for each button press and any other modules involved in processing signals?

Why? I recently installed a new radio with an aftermarket module that converts the controls from the wheel to analog signal for the aftermarket radio. It doesn’t work and here is a troubleshooting summary.

• Does the aftermarket module work with the radio? Yes if I short the leads on the module the radio volume changes. Module is good.
• Do the steering wheel controls work? As far as I can tell, yes. I used a multimeter to get a voltage reading at the wheel. RAVE is pretty vague about this; basically just says the controls are a resistance ladder. The voltages vary by button press so I assume it is working. Though if someone knows the correct voltages I’d be able to better asses that.​​​​​​​

Does anyone know of any other components that sit between the wheel mounted radio controls and the radio harness at the dash? Or perhaps have a better alternative for testing?

 

The RAVE is correct -- the switches produce different resistances. I don't think there is any voltage across the circuit; that is provided by the radio.
Are you using an Android-based radio? You should be able to see the resistances when you have connected things correctly. I've had a couple of units and they have both used only one of the two wires from the wheel (doesn't matter which one) with the other wire remaining unconnected. On the radio, one of the control inputs connects to one of the wires from the wheel and the other connects to ground.

 

Right, there are two wires at the wheel (red, black) and two wires at the harness (pins 2 & 3). I am able to see a difference in voltage/resistance at the wheel but not at the pins in the wiring harness. That’s why I was curious to see a diagram as there must be some other components between the two spots I’m taking readings. Tried to follow the wires on my own but that isn’t feasible unless I take most of the dash out (hoping to avoid that).

Any idea what is between the wheel controls and the end of the harness?

 

Are you checking the resistance between pins 2 and 3 in the grey plug? Because that won't work. Check resistance between either one of those pins and ground. It should change when you press the buttons.




Here's something I copied from somewhere when I was researching mine:Steering Wheel Controls

The wiring for the steering controls functions as the radio reading resistance through the steering wheel controls to determine input. So the radio sends +12v out on Key 1 and Key 2. Key 1 gets wired up to either lead of the steering wheel controls that are in the factory gray radio connector. Silver/red or black/red. You then ground the other wire for the steering controls. i.e. Key 1 connected to the silver/red and then the black/red is connected to ground.

I may have misspoken earlier. I think it may be the other wire from the truck that connects to ground, rather than the second wire from the radio.

 

I’m following most of what you are saying, but can you clarify what you mean by “key”? Is that synonymous with “pin” (I.e. wire in the harness)? The directions I received, Crutchfield, and several posts mentioned pins 2 & 3, so that was what I was using.

 

On the radio, the two wires for the steering wheel controls are often labelled Key 1 and Key 2. You will only be using one of them.
What is the radio that you are installing?