Heyy, so i bought a new aftermarket radio right, i get the right addaptions, the wirings all correct, i got the right interface box thing that cost like 70$ but the radio still wont turn on, i tried checking the fuse and the fuse is fine. When i connect the old radio back in it works perfectly but then i try connecting my new one and it wont get power to the red wire somehow. I even tried connecting the radio to the battery but it still wont turn on. I kept buying and returning radios beacuse i thought meybe it was defected but i dont think the odds of me buying 5 defected radios sounds right. Please help.

 

You are doing this with the battery disconnected right? And you checked the internal fuse on the radio, not in the fuse block?

 

 

So is there voltage on the power wire to the radio?

Is there an additional signal power wire that has to be connected?

And is the ground wire fine?

 

There's voltage all the way up to the interface box but no power to the radio harness itself. im not sure if there's any more wires that have to be connected i just connected the red yellow black and speaker wires, i think the ground is fine cus i just connected black and black

 

The constant wire has to also be connected. I believe it is yellow

edit: nvm i see you said yellow

 

have you tried returning the interface? also are you sure you got the right one?

 

99% of the time it's an installation mistake.

Double check parts and part numbers, and go over the whole process again. Find the wiring diagram for the car side and make sure your harness connects to the right pins.

It's a process of elimination. It's exactly what a paid tech would do.