Wiring issues Installing new radio ('85 325e)

[ThomasE30]

So I bought a cheap 30$ BT, AUX , USB radio off Amazon (https://www.amazon.com/gp/product/B0...0?ie=UTF8&th=1) and I just cannot get a grasp of what I am doing. The radio before this one was some old Alpine CDA105 that needed to be replaced and used a single power and speaker connector. This new one has two connectors you plug in and then adapt to some harness or something. I asked my cousin to try and install it since he used to do a lot of them and he cut the connector that went into the back of the old radio. I now have a bunch of wires just in my ashtray cause he couldn't figure it out and it seems like a mess of cables that were frankensteiened to work together. I had planned to take apart the dash and rewire a lot of the car because there's a lot i just don't understand about the current wiring. He did give me a free sub woofer, speakers, and an amp if he can find it so would it be best to just go get it professionally done? As much as I would love to learn how to do this I just don't want to mess anything up even more than I feel like we have. I will upload pictures later on when it's not 2am lol. Would anyone have an idea how much it might be to have all of this installed if i were to do it professionally?

[reelizmpro]

It appears that they separated the speaker harness from the power/ground/antenna harness for some reason. If you had an Alpine previously installed, find the wiring diagram for the Alpine harness and splice it in with the new harness. It's pretty easy since both harnesses should be labeled. If your cousin cut the alpine harness out, then find the diagram for the 85 325e factory wiring.

[ThomasE30]

I will look into that. Thank you. Here’s some pictures I took so you could see the wiring and then some pics of the connector that was cut off that would be plugged into the old alpine radio. All of those wires in that little cubby by the ashtray are wires that went into the connector but then came out and didn’t go into anything which is why they had those caps.

Edit - It is not letting me upload photos because after resizing them it just says their corrupted so sorry i can't provide any good detailed images. But it looks like all the cables are there but it seems they were all just cut different lengths so i might have to take out the dash. : / I will check out the factory wiring though and see if i can figure it out.