I have a 94 Z28 and if you put the courtesy fuse #8 in, the time stays lit up on the radio and thus the battery drains.

If you open the door with the key off the radio itself turns off as normal but the time stays lit up still. Also, if you turn key off but don't open the door and wait then the 10 minute time delay thing works as it should but still the time stays lit up.

If I take the fuse out the radio turns off completely when the power is turned off but has no memory retention for the stations.

Anyone have a clue what this might be?

 

bad radio

 

Is that an experienced answer or more of a guess?

That's awesome if that's all it is.

 

That's all it can be. The radio has a short in it or something like that. The clock itself shouldn't drain the battery. You could have weak battery or alternator too.

 

It is a common problem with 80's early 90's GM radios, happens lots on third gens

 

the only other thing I can sugest is the ilumination circut could be back feeding. the dimmer switch could be sticking I supose. I would check the brown and grey wires on the radio and see if they continue to get power.

 

Same thing happened on my mom's old 94 Cavalier. Pretty sure it was the radio, but she traded the car before getting it fixed.