Audio Systems: Head unit resets, factory default settings, honda accord lx

Question
Hi Jerry,
     I own a 1990 honda accord LX with an alpine tape casette/radio unit.

The problem is whenever I turn off my car and take my key out the radio resets to its factory default settings. So, I lose my memorized radio stations and other settings.

I believe this is a wiring issue because my car's dashboard clock also resets to 1:00 once I put my key back in the ignition to start the car.

Could both my radio and dashboard clock resetting issues be related? What factors specifically should I be looking for when troubleshooting this problem? Any advice could be really helpful.

Thank you,
   Brett.

Answer
While they may be related (due to the cars' clock having been rewired to a new power source, or a dozen other possible reasons), I can tell you that the alpine should have two wires which need power.

One goes to 'Constant 12v' (that is, a power source which has 12 volts no matter what position the ignition key is in) for station memory (often this is a yellow wire).

One goes to 'Switched 12v' and is usually red.
'Switched' implies that the when you turn the key off, the 12v is no longer available.


As to the Radio memory:
From what you have explained, you likely will find that both power wires are wired to the same power source, but it is possible that is was installed to two different switched power supplys.  
In either case, it will lose station memory and other presets when you turn the key off.

Use a 12v test light grounded to the cars' chassis to locate a constant 12v source. Be sure the ignition switch in the off position  (test light is available at an auto parts store for under 10$).
Be SURE to put a small, inline fuse on the wire near where you tap into 12v (to protect agasinst electrical shorts/fires)!


You may try wiring the cars' clock to whatever (fused) Constant 12v source you hook the memory wire to. ;)