Hi Ford gurus I wonder if I could get a little advice on my problem. Truck in question 1997 Extra cab 4x4 light duty F250, the one that looks like a F150. 5.4 auto 4x4. My issue is when the truck is running, as long as you have the door ajar, so the dome light is on, the trucks charging system is ok according to the ammeter in the dash. Soon as you close the door so the dome lights are off, ammeter goes to 0 along with the speedo. Now its Feb in WIS so driving with door open isnt my best option. Also what might be related, when the truck is off and you close the door the dome lights go off as they should but then the radio comes on even without the key in it. thanks !!

I posted in this forum since its a F150 with just heavier axles i think. Thanks

 

I have no help on the wiring issue, but I know for a fact you don't have a 351 unless one has been swapped in.

 

From what I read, it sounds like you have a short in the door, which is drawing all the power from the alternator. Maybe the power window or power locks are shorting out in the door. What I would do is get a meter, and measure the voltage to the battery when the door is open and closed, and while rolling up or down the windows and locking and unlocking the door locks with the door open and closed. If you get no voltage or very little, there is a short in the door, then you can narrow it down to the window or door locks, possibly power mirrors.
Another issue that may be going on is the ignition switch may be faulty and grounding out. A bad ignition switch would cause loss of complete power to instrument panel, and other things. Also, would be why your radio can turn on without the key in the ignition.
Also, check the fuses to see if they are the correct ohms and nothing is jumped between fuses (a stray wire connected from one fuse to another fuse).

 

^You mean amps for fuses, ohms is for resistors.