Car is a Bmw 325is ('95 btw)
HU is a Sony gt-510.
I have both harnesses for them, yesterday was the second time i tried to install the HU. I soldered both harnesses together so i know the connections are PERFECT but the problem is there is no memory. After hours of trying different things my friend and i narrowed it down to two wires that were causing the problem, the continuous power and the 12v memory wire.
When both are connected with the correct wires on both harnesses theres power but no memory, when all 4 wires are connected theres power but no memory, we tried all the combinations but never any memory. The last thing we tried was skipping the harnesses and going right from the HU to the wiring in the car and it didnt do anything.
Please give me some ideas, i've tried two different harnesses both were brand new and have gotten nothing but a HU that resets itself everytime the car is turned off.