I have a 93 SC 400 with the original amp. I have an after market head unit (Pioneer DVD receiver). Everything has been working fine then yesterday the system stop working and the screen flashes AMP error. Should I assume the amp is gone or could there be other issues?

 

not how its normally wired up usually you run new wires to the trunk and bypass the stock amp on the aftermarket head units. Its hard to say if the error is on your aftermarket headunit, it could be the unit itself, the wiring, or the stock amp since that is still in the loop. check the trunk for water maybe and the amp overall.

 

The aftermarket headunit won't have visibility into the OEM amps operation, its not a 2 way street for communication. That AMP error message is a pioneer hallmark so it's in your headunit. With some judicious googling you might be able to find the reset procedure and theres a chance that will fix it. Not uncommon.

good luck!

 

Just wanted to update you guys. Seems I swapped left and right rca plugs when I did some work last week.As SCereal suggested I googled around and found that amp error is often caused by crossed speaker wiring. So I swapped them back and all is good.

Thanks again for your input.