Blower motor issues?

Thanks for staying with me on this issues I have been having, the air flow drops as I use the gas pedal going up a hill or go faster, but the blower motor still has force blowering. Could it be the relay thats causing this? Its on high speed when it slows down. Should I change the resistor again, its brand new and the relay is also and the blower motor. What a mind blowing thing, hun?

Thanks for the feedback, 1st I checked under the hood and seen that the round vacuum ball hose was not connected, and I see that this was why the low and high speeds as explained in my question, but your diagram did help and will keep for future references. So far, I been checking all the vacuum lines and found one that had trannny fluid inside, not much, but on the one actuator(# 52470773) the plunger is not working. Inow have to find and locate on, which are discontinued, nobody has these, and are hard to find. So I will have to blow out the line with very little air, again (2nd time ) and start my hunt for the part. Thanks for all the feedback so far and will try to solve this weak air issues in my vents. Too hot to be working outside ( 95 - 100 Degrees) the past 30 days here in PA. Will keep you update, Thanks again and god bless for the research you do for me.

Back again. I was wondering, if I replace the blend door actuator located in the glove box and with the new one I get, can I just plug it in b4 I installed it to see if it is working and moving b4 I put it back on top of the door? I know it crazy, but the door does move when I turn it and watching a lot, I mean a lot of YouTube videos, it drives me crazy what to do and mind is manual, do I have to calibrate it? I see a lot say, pull this fuse out and wait 10- 30 seconds with the key on and so on and so on. What is the correct way? I was going to take the blower motor resister out and look and see it the door opens and closes and the close one side to see if the air comes out the vents much better than it has been. This I will do when I get the blend door part today from Amazon. This is really driving me nuts. Yesterday I was out and I turned the A/C on and hot air was coming out and at the foot well. Nuts hu? This morning I turned the a/c on and cold air came out. Man, it this really driving me up the wall. Any thoughts on what I was going to do? My last resort is to tilt the dash and follow my son's advice and make him happy to prove his point and my loss on this one if he is right. He knows I like challenges and he likes to prove his point. Will see. Thanks for your time and your answers on this. I hope to get this issue resolved in the next week. And when I do, I owe you more than a drink!

Ok, back in action. Well, I solved the problem of the weak air flow from the vents. It took time omn my end, son didnt help, checked on alot of YouTubes and came across a video of blower motors by accident. Iwatch it and tryed it and bam, it works. Guess you never guess. Reverse the 2 wires that go into the blower mower! Inever knew it was sucking in air, not blowing it. Once I did that. Holy molley, that god, poped open a beer and ordered a pizza and enjoyed myself. Now, all I have to do is put the new blend door actuator on inside the glove box. Here is the last and final question for you. Do I have to caliber this once its in? I have the manual havc.? All yours now, will wait for a follow up. Tks

Running smooth and will never know how the wires got switch, all was a plug in the back of the blower motor and when I reverse the wires, bingo, full force air, back to normal. I will never know, and now, as long as its working. Thanks again. Will be back if any other problems arise.