Hello,
Having some trouble with my 1999 F150 5.4. It started the other day, truck was running fine, the radio shut off a few times without any notice or reason to. I pulled into my buddies driveway and the windows wouldn't go down. My truck then shut off and would not start again. It would just click and not turn over. I tried Jump starting it and it would start but shortly after shut off. I then replaced the battery and it ran fine for a few days. On my way to work tonight, I noticed my head lights were dim. Then my windows would not go down. The truck ended up shutting off at a stop sign and would not start again. I jumped the truck with a jump pack and was able to limp the truck to work. As I pulled into the parking lot, It shut off again. When I jump the vehicle, it will run, but accessories (windows, radio, headlights) wont work. If I turn on the headlights the truck shuts off. Any suggestions? Thanks,
Justin

 

Get the alternator load tested.

 

That was my plan was to take it to autozone this morning once they open and test alternator. Just seeing if anyone had any other ideas.

 

Your problem is that the battery isn't being charged so, when its voltage drops, stuff stops working, including the engine.

Fully charge the battery manually, the diagnose the alternator/charging problem. If you try charging a completely flat battery with a new alternator, you'll often ruin it.

Make sure you check the field fuse (BJB F11). Also, verify the lamp in the cluster comes on during bulb prove-out. Both ate necessary for proper charging.

Running a new battery down till it's flat usually is bad for it, also....

 

Replaced the alternator. Truck runs great. ThAnk you