Aka640
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- Year, Model & Trim Level
- 2007 explorer xlt
Details:
2007 Ford Explorer XLT
Android aftermarket radio (ATOTO brand but should not matter)
Summary - Replaced blank on the right of steering wheel with radio controls (Junk yard 20$ - did not come with wiring harness)
**I apologize for the pictures they were really only for me and annotated on my phone with my finger**
Through a small amount of research I believe there are two basic protocols for steering wheel controls (SWC), resistive and digital. This write up is for a resistive type SWC.
You will need to remove the airbag and trim around the radio to gain access to required wires, Figure 1.
![20180511_191846[1].jpg](https://www.explorerforum.com/forums/attachments/20180511_191846-1-jpg.159185/ "20180511_191846[1].jpg")
Figure 1: Airbag and radio trim removed
I could not find a schematic for the steering wheel buttons however the following steps should work to determine the pinout on any steering wheel buttons. My controls have four pins (+5, GND, Key1, and Key2 [which output the adjustable resistance based on button press]). Shown in Figure 2 (R1 and R2 are Key1 and Key2 and at the time I assumed it was 12 v, the card does not break at 12 volts by the way)
![20180511_164330[1].jpg](https://www.explorerforum.com/forums/attachments/20180511_164330-1-jpg.159186/ "20180511_164330[1].jpg")
Figure 2: Labels reference pins top to bottom. R1-Key1, R2-Key2, +12 is actually +5, and GND
To identify the pins I used a multimeter in diode mode across the installed LEDs to, 1: verify the LEDs worked and 2: determine which pin was GND (I found that the cathode of one of the LEDs was connected directly to one of the pins - making this pin GND). This should leave three pins. Next I connected my multimeter across two of the pins in resistance mode and pressed one of the buttons. If the multimeter is on Key1 and Key2 you should see the output change from open to some resistance (mine ranges from 230 ohm to 12 kohm). If the output does not change from open to some resistance then you are on one of the Key pins and the +5 pin. Switch one of the leads and try again, if you still do not get open to a resistance when you push a button switch the other lead. At this point you should have all pins identified. For further verification and without risking harm to my vehicles electrical system I attached the +5 volt and GND connections to a benchtop power supply and verified both LEDs lit Figure 3, then verified that with power supplied that the Key pins still changed from open to a resistance on button press.
![20180511_164207[1].jpg](https://www.explorerforum.com/forums/attachments/20180511_164207-1-jpg.159188/ "20180511_164207[1].jpg")
Figure 3: 12 volts shown applied to + and GND pins
Next I had to find where to connect the four pins in the clock spring. For the +5 volt and GND I connected the radio SWC in parallel with the cruise control SWC (Cruise control plug shown in Figure 4). The correct pins can be located using a similar process as above or GND should be easily identifiable in the steering wheel, then with the multimeter in DC mode with the lights on, probe between GND and the other three. One should show +5 volts and the other two will show 0.
![20180511_173127[1].jpg](https://www.explorerforum.com/forums/attachments/20180511_173127-1-jpg.159187/ "20180511_173127[1].jpg")
Figure 4: With the lights on and multimeter on DC mode probed to find + and GND pins, mine read +4 volts on the orange wire with blue being GND.
Next you must locate Key1 and Key2 in the clockspring and the connector behind the radio. I found a similar write up that identified Key1 and Key2 as pins 11 and 10 on the clockspring (Figure 5) and pins 19 and 18 in the connector behind the radio (Figure 6). I verified this with the multimeter in resistance mode and probed between the pins. It does not matter which one is Key1 or Key2 (to the best of my knowledge they are effectively a variable resistor). Additionally the Key1 and Key2 pins can be identified by process of elimination at the connector behind the radio (for me they were the only two that were not connected for other uses).
![20180511_154428[1].jpg](https://www.explorerforum.com/forums/attachments/20180511_154428-1-jpg.159189/ "20180511_154428[1].jpg")
Figure 5: Clockspring connector in steering wheel. The Key pins are the second and third in from the left on the top row, arbitrarily A and B.
![20180511_154507[1].jpg](https://www.explorerforum.com/forums/attachments/20180511_154507-1-jpg.159190/ "20180511_154507[1].jpg")
Figure 6: Connector behind radio. Key pins are 19 and 18. A and B arbitrarily. Also the only two that were not already connected for something. I soldered into the wires behind the connector because I did not have the appropriate parts to connect properly.
The last part is connecting Key1 and Key2 from the connector behind the radio, to the radio. This was the part that I found the least information about how to do correctly. The wiring harness that came with my aftermarket radio did not include connections for key1 and key2 but the wires were labeled coming out of the radio. I connected Key1 from the radio to Key1 from the connector (doesnt matter which actually) then connected Key2 from the connector to GND (Leaving Key2 from the radio disconnected). In retrospect I believe you could just connect one of the key pins from the SWC in the steering wheel to GND (in the steering wheel) and connect the other key pin to key1 in the back of the radio. However I have not tested this.
As you can see I did not describe how I connected any of the wires, there are many options, I soldered all connections except into the clockspring, for this I used a cut standard female header and glued it into the connector.
Once connected I followed the procedure for my radio for programming the steering wheel buttons and to my surprise it works perfectly.
I hope this helps anyone who is trying to do this.
Good Luck,
Adam
2007 Ford Explorer XLT
Android aftermarket radio (ATOTO brand but should not matter)
Summary - Replaced blank on the right of steering wheel with radio controls (Junk yard 20$ - did not come with wiring harness)
**I apologize for the pictures they were really only for me and annotated on my phone with my finger**
Through a small amount of research I believe there are two basic protocols for steering wheel controls (SWC), resistive and digital. This write up is for a resistive type SWC.
You will need to remove the airbag and trim around the radio to gain access to required wires, Figure 1.
Figure 1: Airbag and radio trim removed
I could not find a schematic for the steering wheel buttons however the following steps should work to determine the pinout on any steering wheel buttons. My controls have four pins (+5, GND, Key1, and Key2 [which output the adjustable resistance based on button press]). Shown in Figure 2 (R1 and R2 are Key1 and Key2 and at the time I assumed it was 12 v, the card does not break at 12 volts by the way)
Figure 2: Labels reference pins top to bottom. R1-Key1, R2-Key2, +12 is actually +5, and GND
To identify the pins I used a multimeter in diode mode across the installed LEDs to, 1: verify the LEDs worked and 2: determine which pin was GND (I found that the cathode of one of the LEDs was connected directly to one of the pins - making this pin GND). This should leave three pins. Next I connected my multimeter across two of the pins in resistance mode and pressed one of the buttons. If the multimeter is on Key1 and Key2 you should see the output change from open to some resistance (mine ranges from 230 ohm to 12 kohm). If the output does not change from open to some resistance then you are on one of the Key pins and the +5 pin. Switch one of the leads and try again, if you still do not get open to a resistance when you push a button switch the other lead. At this point you should have all pins identified. For further verification and without risking harm to my vehicles electrical system I attached the +5 volt and GND connections to a benchtop power supply and verified both LEDs lit Figure 3, then verified that with power supplied that the Key pins still changed from open to a resistance on button press.
Figure 3: 12 volts shown applied to + and GND pins
Next I had to find where to connect the four pins in the clock spring. For the +5 volt and GND I connected the radio SWC in parallel with the cruise control SWC (Cruise control plug shown in Figure 4). The correct pins can be located using a similar process as above or GND should be easily identifiable in the steering wheel, then with the multimeter in DC mode with the lights on, probe between GND and the other three. One should show +5 volts and the other two will show 0.
Figure 4: With the lights on and multimeter on DC mode probed to find + and GND pins, mine read +4 volts on the orange wire with blue being GND.
Next you must locate Key1 and Key2 in the clockspring and the connector behind the radio. I found a similar write up that identified Key1 and Key2 as pins 11 and 10 on the clockspring (Figure 5) and pins 19 and 18 in the connector behind the radio (Figure 6). I verified this with the multimeter in resistance mode and probed between the pins. It does not matter which one is Key1 or Key2 (to the best of my knowledge they are effectively a variable resistor). Additionally the Key1 and Key2 pins can be identified by process of elimination at the connector behind the radio (for me they were the only two that were not connected for other uses).
Figure 5: Clockspring connector in steering wheel. The Key pins are the second and third in from the left on the top row, arbitrarily A and B.
Figure 6: Connector behind radio. Key pins are 19 and 18. A and B arbitrarily. Also the only two that were not already connected for something. I soldered into the wires behind the connector because I did not have the appropriate parts to connect properly.
The last part is connecting Key1 and Key2 from the connector behind the radio, to the radio. This was the part that I found the least information about how to do correctly. The wiring harness that came with my aftermarket radio did not include connections for key1 and key2 but the wires were labeled coming out of the radio. I connected Key1 from the radio to Key1 from the connector (doesnt matter which actually) then connected Key2 from the connector to GND (Leaving Key2 from the radio disconnected). In retrospect I believe you could just connect one of the key pins from the SWC in the steering wheel to GND (in the steering wheel) and connect the other key pin to key1 in the back of the radio. However I have not tested this.
As you can see I did not describe how I connected any of the wires, there are many options, I soldered all connections except into the clockspring, for this I used a cut standard female header and glued it into the connector.
Once connected I followed the procedure for my radio for programming the steering wheel buttons and to my surprise it works perfectly.
I hope this helps anyone who is trying to do this.
Good Luck,
Adam
