It's a 1998 Ford Ranger ... all stock. When I turn the ignition off and remove the key, the radio stays on. So my first thought was that it may be the ignition switch. But then I realized maybe there's a relay that is providing accessory power to the radio which could have failed? Or maybe short inside the radio?

Further investigating I think the GEM may be between the ignition switch and the radio? With the key removed, when I pull fuse 20 or 28, nothing happens, the radio stays on. When I pull fuse 29, that kills aux power and the radio goes off and I lose all the radio settings. Does that narrow it down to a fault in the radio ONLY? Or could the GEM yet be the culprit. Both are expensive ...

I don't have access to a schematic so ... I'm sort of guessing here. Anybody else seen this problem before?

Thanks in advance,

R. Medure <!-- / message --><!-- BEGIN TEMPLATE: ad_showthread_firstpost_sig --><!-- END TEMPLATE: ad_showthread_firstpost_sig -->

 

That truely sounds like a short in your switched power to your constant. Forgive me if I make you shake your head, I figure most folks are DIYers here. Where that is a bigger question as there isn't much room behind the dash to trace a wire even worse when said wire dives in to a pack of wires. IF you can pull the deck out (probably consists of dash trim too) the best place to start is right behind the head unit itself as the wires could be pinched or exposed.

This is the first thing that came to mind as I read your post.

 

Does the radio turn off when you open the door with the key out of the ignition?
Could be on a five minute timer.

 

Remove the radio an check the Y/BK wire for voltage with the key off. If you do have voltage you may have a bad ign switch, a wire shorted to power or an internally shorted GEM.