It sounds like the amplifier inside the truck is having a problem. Let's check to make sure the grounds are good and if so, I would try a used amplifier which you can get by searching Ebay. Here is a guide to help us test the ground connections and the radio and amplifier wiring diagrams to help with the testing. You might want to try disconnecting and reconnecting the connectors, sometimes this can help elan the terminals.
https://www.2carpros.com/articles/how-to-check-wiring
It looks like the amplifier is on the right side of the trunk. Check out the images (below). Please let us know what happens.
Images (Click to make bigger)
Thursday, November 30th, 2023 AT 10:32 AM