Owner's Manual

2
Locating the Vehicle Control Wire
Locating 5 volt Resistive Control Wire (Version 3, 8, or 9) White wire Applications
1) Without the factory radio connected:
a. Using a multimeter, attach one test lead to ground and the other to the suspected wire. Make sure that the
SWI or the factory radio is not connected for this test. If the steering wheel ground is sourced through the
factory radio, you would need to have the source wire grounded, or use the source ground wire in the harness
for one connection to your multimeter’s test lead and the other to the suspected control wire.
Version 3: The meter should read greater than 2700 Ohms or infinite while buttons are not pressed. When
each button is pressed, the meter should read a different resistance between 0 – 2300 Ohms.
Version 8: The meter should read greater than 17k Ohms or infinite while buttons are not pressed. When
each button is pressed, the meter should read a different resistance between 0 – 15k Ohms.
Version 9: The meter should read greater than 26k Ohms or infinite while buttons are not pressed. When
each button is pressed, the meter should read a different resistance between 0 – 23k Ohms.
2) With the factory radio connected:
a. It is possible to locate the steering wheel control wires utilizing a multimeter set to test DC voltage and then
use the information in section 1 (above) to verify connections. With the factory radio connected and the
ignition on, ground the black lead of your multimeter and use the red lead to test for the control wire. The
correct control wire (or wires) will show variations of DC voltage depending on what steering wheel control
button is pressed. In cases where there are two listed control wires (Nissan for example) you will get a DC
voltage reading for certain buttons while testing one wire and no response with the other buttons. Test
additional wires to find the wire that provides DC voltage readings for the buttons that did not test previously.
Once you have found the control wires, you will need to locate the wire that provides the source ground for
the steering wheel control circuit. With the radio harness still connected to the radio, place one meter lead to
ground with the meter set to test resistance. With the other meter lead, test the wires in the harness to find
one that shows very low resistance to ground (less than 10 ohms). Unplug the harness from the radio and test
again. Without the radio connected, the steering wheel control’s source ground wire should no longer read
low resistance (it should show an open circuit). If you are still showing low resistance, you will need to plug
the connector back in and continue testing. Once the correct wire is found, you will be able to place one lead
of your meter to this wire and test as described in section 1 (above).
3) In some vehicles (like Chrysler, Dodge and Jeep), you will be directed to find the wire at the steering wheel column.
Using a multimeter set to test DC voltage, attach one test lead to ground and the other to the suspected control wire.
The meter should read close to (or up to a maximum of) 5 volts. When each steering wheel audio control button is
pressed, the meter should read a different voltage. Cut this wire and test for resistance using step 1 (above).