Passenger Rear Window issues on my 2006 tacoma

Ok up to this point I thought I had done all I need to determine that the passenger rear window was bad. I used a volt meter and was able to verify that I was getting voltages to the motor when the switch either switch as being used. At least I verified 12v. So I ordered a new regulator and motor and plugged in the new unit and found that I can only roll the window up. It will not go down.
Could one of the switches actually be causing an issues. I read on some of the forums where others have found that pressing both drivers and passenger switch at the same time will work the window. I in no way can roll down the window.
Other that the switch on the drivers panel that locks disables all the windows, is there anything else that may cause this problem?