New head unit works fine on the bench, not in my car.

[Solidsnake]

I installed a Sony head unit a few years ago and it worked fine up until a month ago. All of the sudden it became unresponsive and would not function properly. Aside from being able to turn the volume up and down I could do nothing else. I pulled the unit and bench tested it and it was still unresponsive. I ordered a new Pioneer head unit from eBay wired it in and it did not function properly. It played fine but I could not pull up the menu to go into the system settings, control my iPod, etc. The remote would not work either. I sent it back and got a new one. Same problem...

I pulled the unit out and bench tested it and it works fine on the bench, not in my car. This tells me the problem is my car/wiring and not the head unit. I double checked my wiring and everything is fine. I also tested the ground when it screws to the chassis and it is fine as well as the additional chassis ground.

Any ideas as to what to check next? I am hoping that someone can steer me in the right direction.

Thanks in advance for the help!

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[CSCStang]

I installed a Sony head unit a few years ago and it worked fine up until a month ago. All of the sudden it became unresponsive and would not function properly. Aside from being able to turn the volume up and down I could do nothing else. I pulled the unit and bench tested it and it was still unresponsive. I ordered a new Pioneer head unit from eBay wired it in and it did not function properly. It played fine but I could not pull up the menu to go into the system settings, control my iPod, etc. The remote would not work either. I sent it back and got a new one. Same problem...
I pulled the unit out and bench tested it and it works fine on the bench, not in my car. This tells me the problem is my car/wiring and not the head unit. I double checked my wiring and everything is fine. I also tested the ground when it screws to the chassis and it is fine as well as the additional chassis ground.

Any ideas as to what to check next? I am hoping that someone can steer me in the right direction.

Thanks in advance for the help!

How did you check the wiring? Multimeter? Test light? Did you use a factory to aftermarket adapter? Definitely a harness issue.

 

[Solidsnake]

How did you check the wiring? Multimeter? Test light? Did you use a factory to aftermarket adapter? Definitely a harness issue.

I checked the grounds with a power probe and used a Scosche wiring harness.

 

[CSCStang]

I checked the grounds with a power probe and used a Scosche wiring harness.

Try bypassing the harness for your power and acc. Run the hot to the battery and the acc to a switched (power with the key on) source and see if it powers up correctly. If that works, you can leave it that way.

 

[Solidsnake]

Try bypassing the harness for your power and acc. Run the hot to the battery and the acc to a switched (power with the key on) source and see if it powers up correctly. If that works, you can leave it that way.

Thanks for the input. I will give that a try.