What part do I need and how do I fix my heater? Is it the AC control module? on 1998 Oldsmobile Bravada

My car used to blow hot air out the vents like it was stuck on auto all the time in summer and winter while driving even if the heater turned off. The control would also still work going from 1 to 4 as well. During that time my ac worked at first then stopped working as time passed. Now my heat all of a sudden does not work. The lights on my control panel for the ac and the defroster doesn't light either. Its like the whole control panel is dead where the fan blows out cold air constantly on low but does not react to the control switches from 1 to 4. nor does the temperature work from cold degrees to hot degrees (they do show the temperature numbers). I took it to Meineke repair shop and they told me it was the blower motor resistor control module but when they attempted to get the part as it was not available but at the dealer they were not able to fix it as the piece from the dealer would be a lot more. They said my car had a different resistor than the other ones something about the climate control. I ended up getting the part but the part after description and me taking the part out to show was actually the AC control module as it was different than the blower motor resistors that were being uploaded up from the auto stores. Thinking I had the problem fixed I get the used part from the junkyard, the AC control Module, and fastened and plug it back on but my heater still does not work and the control panel still is dead with no lights coming on for the ac or the defroster. Am I missing something like I need special equipment to fix it? Is it another part? Please help, its only getting colder out and I do not want to keep driving in a cold car to work. (I was told the blower motor still works)

Asked by for the 1998 Oldsmobile Bravada
seek help as not to waste your money on guessing
Already told him - see his response, ' need a quicker fix'.
see just as we talked about the other day
Yep 3in of sleet here today burr
1 more answer , 3 more comments
Before spending more money on parts, unless you have plenty to spend, find someone with a Tech2 scan tool. The system function can be monitored or controlled by this tool. You can find the problem then fix it, instead of trial and error.
sounds fine but the looking around could take longer. need quicker fix. Is there any reason other than its not the AC control module part that this replacement part did not work? and if not what else could be or better yet what is the problem?
You don't understand how the system operates. I could tell you many stories about these system repairs, and some have the same symptoms with different fixes. I have learned on these it's better to scan the system first and find it instead of being a parts changer. If you replaced the control module with a good one then I would trace the power and ground circuits first, with a scan tool I can read if that part is working without having to pull parts and manually trace. Need a diagram try
Are these modules the same for Bravadas, Jimmies, Blazers, etc with ATC ???