SOLVED Yes I said solved
I have had my 99 ML320 since 2000. It has 189,000 miles and it seems like I have had to replace almost every nut and bolt with breakdowns increasing over the years. I have had the vehicle maintained and above and beyond as I have cancer and after the divorce, guess who got the "non-new truck, car, van"?, I rely on my ML. I keep the exterior in good condition as well.
HOW TO FIX THE 99 ML320, in this case front passenger side, power window when it will NOT GO UP!
1. Get a pair of pliers (putting electrical tape on both sides is recommended so it won't scratch anything, and open up the players to their greatest width
2. Put the pliers on both sides of the switch not working (it helps to put the pliers towards the front with good tension)
3. Gently rock the switch left to right with an occasional backward pull and the black power window switch will come off leaving a white/yellowish plastic "skeleton"
4. Gently pull the white/yellowish plastic skeleton up as you normally would to put the window up and give it a few moments to engage
5. It should work, as I have had to do this at least 6 times over the years and it always worked UNLESS the actual power window regulator/motor is broken, and though this is temporary fix it will get the window up
LAST BIT OF ADVICE - there are 2 very good YouTube videos that walk you through,, and I am not a mechanic but I was able to do it easily after buying the 4 power window switch panel online with a warranty, (1) HOW TO REPLACE THE 4 SWITCH PANEL AND/OR (2) HOW TO REPLACE JUST ONE SWITCH IN THE PANEL. Either of these will take you step by step in real time and it took me about 15 minutes to complete and PLEASE use screwdrivers that are magnetically made (i.e. so it will hold onto the screws after removal) AND I recommend that you take the largest refrigerator magnet, turn it over so the magnetic side is face up, to put the screws onto so they won't get lost.
THANK YOU to everyone at www.benzworld.org
and to the members whose advice has literally saved me thousands. Take care