I'm trying to install an aftermarket radio into my 84 f250 but I can't get it working. The radio is a kenwood KDC-135. I know it has power to it because I can hit the eject button and it will try to eject a cd. But the display will not come on. I don't know where to begin or where to end..

 

Do you have the wiring diagram?
http://manual.kenwood.com/files/B64-3691-00_00.pdf

There are two power sources (one keeps the memory alive, the other powers the unit). see page 15.

Do you have both of these power sources connected?

 

There is a wire called the clock lead that I have hooked to the ignition wire. Doesn't make sense that the radio isn't displaying anything unless the radio is shot.

 

You never answered Bumkin's question:

 

The deck has to have red to switch hot and yellow to constant hot. To have the deck function both have to have power. The eject mechanism may work, or try to but in order to function correctly has to have a power source to both deck wires. If you have the deck out you can test it by the battery terminals. Red and yellow on hot and black on ground. If you need help we will help but you need to let us know you follow the info we give exactly. If not it wont work. If you need wiring help after you get a working deck or get this deck working let us know. I will tell you how i wired my xplod head unit if you need.