I seem to recall a diagnostic mode for these stereos.

I *think* it goes like this:

With the radio off, but the key in the ACC position, hold down the 1 and 6 buttons, and press the CD button 3 (or 6?) times. It will beep a couple times and check itself out, and you'll be able to use the up and down rocker to scroll through any error codes.

What you can do with said codes I don't really know <img src="/forums/images/graemlins/zombie.gif" alt="" />

My Truck: 1987 XtraCab DLX 22R 4WD 5 Speed Manual
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"Speed has never killed anyone. Suddenly becoming stationary, that's what gets you." -Jeremy Clarkson