First off, thanks in advance to everyone who may be able to help me. I just registered to this site but I've used it multiple times before when addressing problems with my truck. I actually saved $250 after hearing a dealership tell me my truck needed to be shipped off when I used a poster's simple advice of changing out a fuse, and it only costed me $15. Now to my most recent trouble with me truck:

To start off, I drive a 2004 F-150 2WD Lariat. On start up, everything works fine. The gauges work normally, the AC cools, the radio cranks up, and all of the power windows/locks work fine. After driving a bit all of this changes. All of the gauges will quit working (Speedometer, gas gauge, etc), the radio turns off, the AC still blows, but it blows hot air. Then, after a couple of minutes it will all come back on, only to go back off. There's no set time in between when it's working and and not working. It's a bit alarming when this goes on because the speedometer goes out I can't tell how fast I'm driving. The odd part about all of this is that, if I turn the truck off in the midst of everything being out, and then I turn it back on immediately, everything comes back on as if it never were out.

I apologize for the long text, and thank you to anyone who is able to assist me on this.

 

I'd recommend you get your battery and alternator tested to start with. Parts stores can do basic tests in the parking lot without removing them, and it's free.

 

Voltage regulator is bad in the alternator. I had to replace mine because it died and the new one I put in was sending 16v out to the system and caused it to do exactly as yours did. Put in another new alternator and everything operates normal now. The electronics must have been shutting down due to over voltage. Funny thing was when NAPA bench tested the new bad alternator, it tested good. While in my truck though we put a multimeter on the battery and that's when we discovered it was sending out 16v.