2 days ago, I removed the aftermarket head unit from my 1995 Toyota Pickup to install an updated one with bluetooth and a USB port. The radio I removed worked and I didn't do anything drastic just wired the new pigtail to the stock wiring. I have checked the wires several times to make sure they are in the right locations. They are all correct and the radio does not work. I thought at first it was the radio. So I checked the fuse on the back of the radio and the radio fuse in the truck and all are good and not blown. Next, I got out my test light and decided to check the pigtail I wired up. There is no power to any of the leads that go to the stereo. So, naturally I took my test light and checked the fuse block and there is power to the fuse block in all of the fuse positions. So somewhere between the fuse block and the radio I lost power to all of the leads. How did this happen? What am I missing?

 

After a few more hours of research and diag I think that I have found the culprit. Does anyone have any experience with the integration relay going bad? I disassembled the integration relay on the back of the fuse box and found that the circuit board had a burn mark on the back. I have power to everything except the stereo. All of the wiring is good and this is where tracing back took me. If there is anyone out there that objects to this please let me know so I can go a different direction.