Very good answer ray if this is happening with both the passenger switch and the master drivers door switch or just the passengers switch first if it's both please take off the master switch connector and clean the pins on the switch and the inside of the contacts on the connector use alcohol and a lite abrasive corrosion will limit electrical passage at those contacts and stop the power going to the passengers switch also inside the switch there are contacts that can get burned and fouled out if after cleaning the connections it still doesn't work you will have to open the switch itself and clean those button contacts on the copper arms do not put grease inside it will make it worse and maybe shorting out all together so you must be more specific here and I mean is it just the passenger switch thats not working or is it both my answer applys to both switches if it's just the passenger switch same thing do the pins the switch connector and if still a problem take that switch apart and do those copper arms button contacts good luck stephen

Your window switch is faulty. You have sufficient voltage to make the window go down, as the power needed is low. You may have sufficient voltage To make it go back up, but I suspect that there is insufficient amperage to make it work. Your switch is absorbing the amperage needed to make the window motor work. Putting a volt meter on your switch will tell you all is working, but also check the amperage in and out of the switch. If less is coming out, there's your problem!

Replace switch. Too much voltage drop when uder load.