I pulled my head unit out of my 2004 mazda 6 today, to access the back of the radio. I wanted to install a FM modulator for my Sirius Sportster 5 plug and play radio unit.
The install went just fine, but now the Dash LED lights for clock, temperature, and radio controls doesn't light up at all. The buttons apparently work given that they still make sounds when pushed, but no display.
I didn't have to unplug any of the wire harnesses to get to the back of the head unit, and I checked to make sure everything was plugged in tight before I put the head unit back in.

Can anyone suggest something I might have done to cause this, a way a might be able to fix this, or any troubleshooting steps I might take to remedy this situation?

Thanks for your time.

JB

EDIT: I just checked the right **** that controls radio station tuning. It won't change the station when you turn it. It makes a noise when you push it, but thats it. normally if you push it once it lets you adjust bass, twice lets you adjust treble, then fade, and balance. I'm not able to adjust any of these, since turning the **** appears to do nothing.

 

Well, I can think of at least 4 things it might be:
1) You don't have the connector(s) in all the way even though you may think you do.
2) LEDs accept, and only work with DC current and something is wired backward.
3) The room fuse in these cars seems to have strange effects on things if it's not making good contact, has become corroded or is blown. Check that out also.
4) You may need to reset the ECU. I know this may sound silly, but it has worked with radio issues before.
If all else fails, disconnect the battery for 10-15mins. During that time turn on all the electrical devices you can think of to drain any residual current (capacitors) in the ECU. i.e. Hit the brake pedal, turn on lights, turn the ignition switch to on, etc. Reconnect and see if you radio decides to cooperate after that. Keep in mind though that you will lose your tripometer setting as well as stations saved and clock settings. You may want to write them down before trying this.

Also, why did you cross-link to mazda6club forum in your post? Most forums would frown on this, linking to a competing site.

 

How would I reset the ECU?

From what I've read you can reset it by doing the last steps you suggested (disconnecting battery, etc).

Is there another way to do it?

Thank you very much for your help. It is greatly appreciated.

 

That would be the way to do it.
What's the problem? A 10mm wrench and the time it took to start this thread is all it takes.
No problem.

 

Is your "home-away-from-home entertainment center" fitted with an anti-theft device ? Quite a few are nowadays; if you tripped it, you might have to have it reset by a dealer/ vendor.