From your description you have a major electrical fault. With the items you are describing it sounds like the main electrical fuse box under the hood or the battery cable that feeds it. The first step I would do is remove and clean the battery cables at both ends, both positive and ground and ensure that the engine to body ground and engine to frame grounds are also in good shape and clean, then I would check the individual grounds on the engine block as well. Now see if the dash and radio work properly. If they are still off then it's going to require testing the circuits themselves for that I would start at the fuse box under the hood, they are a weak spot on some GM trucks as they corrode underneath, and you cannot see it because it's all underneath the plastic. For that you disconnect the negative battery cable, then pop the cover off the fuse box. Now remove the three power feeds from the end and the two nuts inside. Next you pull up on the box until you can get to the connectors. They only fit one way so pull them off and remove the fuse box, now examine the connectors on the box and on the wire ends, you are looking for damage or green corrosion. Or rodent damage. This is a good video on the panel and its removal and inspection.
Now if you do this and it's still acting up you will need to isolate which items exactly do not work and then start determining what they share. The above should get you started. Let us know what you find, and we can proceed or if you take it to a shop, you will have an idea of what they might try. If you are in an area near saltwater or a region that uses salt on the roads corrosion in the boxes is common. As is the rodent damage.
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Saturday, January 21st, 2023 AT 12:27 AM