Ghost in the electrics?

[Mike Arman]

Got a strange one . . . looking for some ideas.

86 5Ks - strange electrical problem.

Took a 65 mile highway ride Sunday, when we arrived, the radio wouldn't go
off. (!). Radio is a Blaupunkt AM-FM-CD, standard wiring, no special
tricks, power antenna. Normally, switching the ignition off shuts down the
radio, and the antenna retracts.

This time, with the ignition turned off, the antenna stayed up, and the
background lighting on the radio remained lit, even though there were no
LCD numbers showing, nor was there any sound from the speakers. Cycling the
ignition and the radio controls did nothing - no response.

I removed the faceplate, put it in the trunk, and went away.

Six hours later, I came out, replaced the faceplate, and the car started
right up but the radio remained dead. (My guests asked me not to sing
instead.)

Arrived home, radio still dead, background illumination still on, antenna
still up. I'll fix it tomorrow. (Took faceplate inside.)

Now it is tomorrow - and the radio has killed the battery! Jump start car,
drive to bat cave (my office/shop), pull radio out of console. Fuse not
blown, radio works fine. Battery on charge now.

I'm trying to determine the failure mode of the radio that would kill the
battery and then heal itself . . .

Another datapoint: Last summer, I made a similar trip, also about 65 miles
of spirited highway driving, went to an event, and came out about six hours
later to a dead battery! In that instance, I *think* I may have left the
lights on (in a hurry, morning fog, not awake yet), and a jump start lit
the car up with no further problems of this type until yesterday.

Battery is about three or four years old, and remember that I'm in Florida
where is (usually) doesn't get very cold so batteries don't work too hard.

Is this a radio problem, or is the confused radio the symptom of a battery
or charging problem?

Best Regards,

Mike Arman