Hi I have a 03 Honda Accord ex 2.4 only had it for about a month.Radio worked but I had no code but it still was on.got the code and the second day driving listening to the radio it just shut off.The ac/heat buttons still work.I bought a factory navigaton Honda unit and tried to plug it up but nothing cut on except for the heat and ac. My original radio said 7bk0 I tried to install one o found at junkyard from 07 that had Xm.it didn’t power on but ac worked.are the radios not interchangeable or what.i hope I don’t have wiring issue.if so what tool can help me find if it does or doesn’t.

 

you can't exchange headunits for different years or even different trim levels. most of the navi units had external amplifiers and required more connections.

measure voltage at the radio harness to ensure you have both constant and switched ignition. the 03 units had high failure rates so you may be finding used radios that don't work either.

I've done a swap to a higher trim level radio out of a newer year and I had to study the schematics for both and modify wiring to make it work, which included cutting and soldering factory wiring and I had to have all of the wire harnesses for the new radio (cut off a few inches back).

 

 

The first step is to visit https://techinfo.honda.com
From there, you will need a 1-day subscription where you will need to download the radio schematics for your car and for the donor vehicle (where the head unit comes from).

Next, you need to compare the wiring requirements for the two units and determine what to do with every wire from both systems. In addition, you will need to determine what other external components are needed, and you will need to re-wire all of those components. I would expect this effort to take 15-20 hours to fully document.

A Digital Multi-Meter (DMM) is the tool that measures voltage and resistance.