2002 SCrew Lariat FX4

So, today, driving down the road, I actually watched my battery gague fall from mid-point, to below the "low" marker...totally flat-lined. My entire instrument cluster went dark, but the ABS and battery LEDs were lit. So, I figured I'd better head on home before I actually turned it off. Boy was I right. I pulled into the garage and turned it off. I waited a moment, then tried to start it again. All I got was the familiar "click, click, click, click" of a dead battery. The strange thing is that my battery is less than 2 years old. I can't figure out what is causing the issue. I checked all the fuses and relays and they're all just fine and dandy. The only thing I've changed in the last week is I swapped out my OEM air intake system for a shiny, new chrome cold air intake. However, I fail to see how a CAI could have anything to do with an electrical issue. Could it be my alternator? When I have the hood open, and I'm standing over on the passenger side, near the battery, I can hear a faint click about every five seconds or so...sounds like it's coming either from between the battery and the firewall, or somewhere behind the firewall. Could whatever that is, be the issue? I have it on a charger now, but if it is something like the alternator, my charging the battery is truly a fruitless effort. Any ideas? Thanx.

 

Update:

I had it on the charger for a little over an hour. It started right up and drove fine. When I returned to the garage, I powered it off. Then placed the gagues in test mode and started it up again. While in test mode, I came across one of the displays that alternated between "ee fail" and "ee 01." In addition, the battery LED started to come on and flickered in what appeared to be a completely random pattern. Any ideas out there at all? Thanx.

 

Search is yer friend:

https://www.f150online.com/forums/el...d-battery.html

https://www.f150online.com/forums/el...t=battery+test

https://www.f150online.com/forums/el...t=battery+test

https://www.f150online.com/forums/el...t=battery+test

https://www.f150online.com/forums/el...t=battery+test

https://www.f150online.com/forums/el...t=battery+test



Perform tests as indicated. Good luck.

MGD

 

I yanked the alternator, ran it to AutoZone, and had them bench test it. Needless to say, it failed miserably. I got myself a 130amp replacement and was up and running again in about an hour. The most difficult part of the whole replacement process was the belt tension. Thanx for the guidance!