Factory radio/cd player won't work when cold outside

I have a 91 Tbird with a factory premium sound cd player/radio. It will = not play until the car is warm inside. The clock will not display either = until the radio works. To get the radio to play I have to restart the car after the interrior = is warm. I have to drive about 12-15 miles with heat on full blast then, = if on expressway (which is the case on the way to work), put it in = nuetral, turn it off, restart it and put it back in drive. This can't be = good for the trans. Is this no play cold radio thing a common problem?

Yes, I know. I can hook up a test light or voltmeter to the power wire = where it goes into the radio to check to make sure it is getting power = when cold. I haven't had time nor would I know which wire to hook it to. This is possibly an ignition switch problem as well.=20

I would like some insight before I start shooting in the dark at this = annoying problem.

Any thoughts?

Dan

it goes into the radio to check to make sure it is getting power when cold. I haven't had time nor would I know which wire to hook it to.

This sounds more like it could be the internal power regulation in the radio itself. If possible I'd take the radio out and try to run it off an external DC supply.

If there is a "kinda dry joint" or a semiconductor that's got a broken bond wire, or a resistor that is just too low a value until it warms up, you could have an internal power rail that takes a long time to come to nominal voltage. Microcontrollers don't like slowly-rising power rails. The reset circuit in the radio is probably a simple RC that can't cope with a situation like this. So when you turn it on cold, it crashes - and you need to "reboot" it (effectively) after resolving the brownout condition.