Toyota Repair: 4 Wheel Drive Question Toyota Tacoma, drive question, 4lo

Question
Hi Ted,

My four wheel drive light on my 2004 Tacoma does not come on.  With the ignition on, and pressing the 4WD button on the lever, one can hear the actuator assembly at the ignition switch operating.  You can also hear it when you move in and out of 4WD Hi into neutral but not when you move it in or out of 4Lo.  I went to use 4WD the other day when it snowed and noticed the light not coming on and no 4WD operating.  Any ideas??

Thanks,
Dave

Answer
It may be a problem with the ADD actuator located on the front differential, there is a way to test the system requiring disconnecting some connectors and the use of a multimeter, I can send some illustrated test procedures directly to you but I would need an email address.