I have a '98 accord EX 4Door. I put in a new haed unit, And now my clock doesn't turn off, even with the car turned off and the key out. I don't know if it turned off before, I never really checked, but did something get damaged when they installed my head unit?

 

if it turns off...den my clock is broken 2... hahaha, i think its normal so don't worry about it.

 

new head units have an illumination wire that controls the display brighteness during the day and at night, I imagine that this wire has affected your clock staying on by bypassing some circuit

 

Does your radio turn off with the key? If the constant power and switched power leads behind the radio are touching, it will feed power back to the accessory circuit and keep the clock on. Check to see if anything else works when the key is off that's not supposed to (lighter, wipers, etc.).