I have a 2004 expy with the 2v 5.4L motor with 120k miles on it. Just today started having issue with whole truck losing electrical power for about 3 secs while driving.


Started up truck and headed out and just a bit down the road all power went off, I coasted to side of road and in a couple secs the radio and AC turned back on. I turned the truck off then fired back up fine. It happened earlier in the day to the wife but trying to get info from her is hard so I took it the rest of the day. Battery is not too old and the alternator is new about 2 months ago; replaced when I was trying to find source of whining from the engine (turned out to be an idler pulley). No codes and other then this the truck runs great

Very strange, I have never encountered anything like this and hoping you guys may have some info

 

I would check your battery connections. The F150's are power hungry and I noticed that with a normal battery there is a fair amount of off gasing that causes a bunch of corrosion on the terminals. I switched to an Odyssey AGM battery when my last battery failed a few months ago so hopefully that will no longer be an issue for me. If your terminals are good then I would confirm the battery is good and the alt is charging like it is supposed to. You may have an issue with the cables themselves. I have seen that several guys here have had to replace them.

 

Start by cleaning the battery terminals.

 

I'd also check the main power connection on the alternator.

 

If you had the alt installed by someone take back to them. Have them check it out.

If you did it go back and check everything. Like the other person said make sure the alt is working properly and battery is doing good.


good luck

 

Looks like the battery terminal connector is shot. It is an aftermarket one that one of the wraparound pieces is broken so not getting nice tight fit. I will get a new one tomorrow and replace it. Hope that is all it is.