Steering Wheel Controls
The steering wheel controls are momentary switches connected to pins P and N of the harness. They short these pins with various levels of resistance which is decoded into the various functions. I took apart my MPV's head unit and read the resistance on the functions it has. I then tried this control with my Miata's 4H60 head and the controls all worked perfectly. So this might presumably work with all FMS double-DIN heads!
| Application | Resistance |
|---|---|
| Mode | 1k Ohms |
| Vol+ | 150 Ohms |
| Vol- | 60 Ohms |
| Track | 300 Ohms |
| Mute | 2k Ohms |







