So Thursday afternoon my battery light came on when I left work. It went off right before I got home, so I just kept an eye on it. I went fishing at Grapevine and when I started the truck, nothing happened. I got it jumped and limped home with REALLY dim lights and lots of weird noises when I hit the turn signals or brakes. Take out the battery, go to get another one. They tested the old battery and said the battery was dead, so I figured I'd got the problem. With the new battery, it was fine. No light, no weird sound on the radio when I hit the brakes or hit the turn signals. This afternoon I go run a few errands and on the way home I notice the light is on again.
I'm afraid it's the alternator.
1. Anyone have any battles with this?
2. How big of a hassle is it to change out the alternator?
3. If I need to take it to a garage, how much am I going to be out on this one?

Thanks

Here are some directions I found on the net to replace the alternator.

Remove Alternator from 1999 Expedition

1. disconnect battery
2. remove platic cover over air intake at the top of the engine. 3 screws.
3. remove flex hose from air filter to air intake. 2 hose clamps.
4. use 1/2 inch drive to loosen tension on serpentine belt. use a cheater pipe to extend the length of your ratchet handle to make it easier.
5. remove 3 bolts from alternator.
6. once the alternator is free, wiggle it around to make removing the electrical connections easier to get to.
7. remove the two plastic electrical connectors and one wire connected to the alternator. Use a small screwdriver or awl to rpy the plastic connectors loose.

Takes about 1.5 hours to remove old, install the new one, and get the engine running again, if you have decent tools.

Have the alternator tested at AutoZone before you buy a new one.

Easy Fix Jay.

Anyone that can use a screw driver can change an alternator out.

A couple of bolts and wire harness plug, and your done.

The prospect of fighting with that giant serpentine belt just kills me.

Sounds to me like you need to invite Fish Killer over for some ice cold beer.

That belt is easy to swap. You may as well replace the belt if you have never replaced it as well.

the belt takes all of about 30 seconds to remove. Just use a big enough cheeter bar. The part that is going to kill you is when you take it to Auto Zone and ask for a replacement.

OK, fixed it today and everything is gravy. Thanks for the help guys!

Now if I can figure out what I did to make the heater kick on after the AC runs for about 10 seconds, I'll be golden.

Thanks again,
Jay

OK. After a long fight with this thing, here's a warning for the future incase anyone searches for a similar problem.
As stated, I initially thought it was the battery, then the alternator...
I replace the alternator, put a freshly charged battery on it and it still craps out. I take that alternator out, take it and have it put on the machine and it tests fine. At this point I'm $190 into the project and decide to take it to a garage before I waste any more money on dead end solutions.
As it turn out, on that 5.4 liter Triton engines, there's a separate coil for each spark plug. One of those coils had gone out and was causing the whole charging system not to work correctly. $160 later and things are working perfectly.
So, next time your Triton 5.4L starts to act like it has a bad battery or alternator, have those coils checked.

Wow! New to me.. Glad your vehicle is up and running.

Did some research and still dumb founded as to how the coil is tied in with the charging system. Was the vehicle running on 7 cylinders? I'm still lost at this one!

The coil is absolutely not tied to the charging system. I don't care what anyone tells ya ! Unless the coil grounding to the engine was causing some interference.

The only connection could be this: The coil will cause a rough idle condition. This low or rough idle condition might cause alternator output to be reduced..

I have an 01 expedition. We have now replaced 7 of the 8 coil packs at various times.

Just a note- Auto Zone sells the coil packs for about 45 bucks each.. Very simple fix on all of them except # 8.
Even #8 can be done in about an hour..

What you gotta watch out for is when the spark plug blows out of the hole, caused by only 3 or 4 threads into the aluminum head..
That one will cost you some money. LOL

LOL, sounds all to familiar!