so i have a 2000 ford f-150 XLT just bought it like 2 weeks ago and drove fine no problems then the other day it just lost power completely and would act like the battery died so changed the battery and it was fine for awhile then it happened again but now it wont even start at all but it has power i don't think its the alternator because i was watching the battery gauge and it didn't move till it just randomly died but when i try and start it it makes one click then loses power till i let go of the ignition I've replace the starter and the solenoid checked all fuses but they were good and i heard the fuel pump turn on and it had 14 volts when jumping but will still lose all power when i turn the key and my obd reader shows no codes but before it have an evap code so maybe a bad ecu?

 

When you say "won't start" do you mean won't crank? Or cranks but won't start? The last comment implies no crank but it's not clear what happened before.

Those are two very different situations. Sounds like bad connections somewhere.

Clean your battery cable connections.

 

ill turn the key hear a click then zero power kinda sounds like the starter trying to activate

 

Something may be locked up mechanically.

Remove the accessory belt and see if it will start/crank. Won't hurt to run it for a minute without the belt.

If it doesn't start/crank, see if you can turn the engine by hand.

 

There might be some clues in how it died. Is it an automatic or stick shift? Were you driving or was it sitting still?


Locked up engine kind of fits the symptoms. Could be the AC compressor, as Jon Freeman's suggestion might show.

I'm going to guess that you aren't sure of how to remove the belt. Here's a good video. Good luck.

 

ill give that a shot tomorrow thanks and i was driving when it just died dropped from 14 volts to 0 instantly but I've changed belts before I've mostly worked on my car and its never acted like this truck has I've done everything i could think of

 

Definitely check for loose wires/battery cables as mentioned.

 

Merry Christmas
Spank that instrument cluster around some just in case
Cracked solder joints and the like make the cluster functions inoperative at times (intermittent loss of everything)
Check the grounds behind both kick panels
You did verify the engine turns over with a ratchet and socket on the crank bolt, correct?