Here's the outcome...
Winnebago's guy told us that there was metal all along the side of the MH where the brackets would be placed. (I gave him the serial number of our MH). I am sure that I told him the brackets were going below the awning rail. Besides, you'd think they would know that brackets MUST go below the awning rail... or else they would interfer with the movement of the awning.
When we drilled the holes for the brackets... we didn't find any structure material for the rear bracket. The old awning was at 19 ft. We could put the awning arm down the side at that point because the dryer vent was there. We went a foot longer ... and were totally taken by surprise when we drilled holes for the bracket and did not find anything to hold that bracket to the side.
I called Winnebago back... talked to the same guy... he was SURE that there was metal all along the side of the MH. I asked for him to send me the drawing he was looking at. He emailed me a PDF. As soon as I saw it, I knew, he did not have a CLUE where the brackets go. (They go BELOW the awning rail.)
Hubby made a bracket that he attached to the awning arm which enabled the awning arm to hang from the awning rail. Then he secured it below the awning rail, too. (So all the weight is on the awning rail.)
See for yourself... We DO NOT have any official engineering training. If you do this.. do this at your own risk.
Pics and Videohttps://picasaweb.google.com/117253848546820846335/9100DometicPowerAwning?authuser=0&authkey=Gv1sRgCK2MuY2opt-w1gE&feat=directlink
Kathy