Howdy folks - hope someone can shed some light on this.

Yesterday evening, at work, a co-worker needed a jump so I helped them out. For whatever reason, the jump didn't work. They got some power (lights turned on) but the car wouldn't turn over. Tried my cables on another car, and it worked fine.

Later that day, on my way home on the highway, I noticed my interior lights were getting dim and the wipers were slowing down. Turned on my hazards, pulled off an exit and got off the road. But the time I reached a parking lot, all my lights were off, radio was off, etc, truck still running. Shut it off, couldn't start it again. Got a jump, it worked, but wasn't even able to shift it in gear. Got a ride home and left it overnight.

Went back today, took the battery out and had it tested. Wouldn't charge, but had it on warranty and switched it out with a new battery. Installed it, truck started right up with no problems, but the battery light on the dash would come on intermittently; usually when I was at a stop at a light or slowing down dramatically. Got it home safely, but the light worries me. I kept all of my electronics off while driving - radio, heater, lights, etc - with the exception of the wipers (I live in Portland. Doesn't stop raining).

So, my question, is something else wrong here? Could the alternator be bad? I opened up the fuse box on the passenger side, and looked at some diagrams, but I couldn't figure out which one was for the alternator, but I'm assuming if a fuse was bad it wouldn't have started ...? What would be my next step in troubleshooting this?

My knowledge is very limited, if you can't tell. I know very basic things. You may need to talk slow. Someone mentioned it being cold, but the weather here isn't that bad. maybe 40-45f

It's a 6cyl 2006 Ford F-150 with about 180k miles on it. Had it for about 3 years now, only problems so far have been replacing the battery last summer. Any help would be appreciated. Thanks!

 

Take your truck to the local Advance Auto Parts store and have them do a Charging System Check. That'll show how well (or how poorly) the various charging system components are working. They can / will also read any codes for free. That will tell you what direction you need to head in better than we can.

BTW: That's exactly the reason I refuse to use jumper cables. I carry a jump box instead so I don't risk my truck's electronics by being a good Samaritan. Hope it all works out for you.

 

The problem may be the cable. Check both ends for corrosion. I mean at the starter too. The cable could be corroded internally.

 

Same here!

 

First -- Good job!

However, sadly, don't use modern vehicles to jump start! Not good for them with all of the sophisticated electronics. I got a buddy who does wrecking, and he was firmly told NOT to use the tow truck to jump. They are each equipped with 3 jump packs at all times in their tow rigs.

I have one in all of my vehicles, and I routinely check them every 6 months.

Speaking of being a good Samaritan getting backfired: I dug someone out of a snow bank at my work two days ago. As I was digging them out (mind you, I was in jeans and a hoody soaking wet at this point), one of my security guys comes rolling in his truck, rolls down the window, and asks if I needed help. I say, yeah, "Grab this shovel and start digging them out in the front, while I dig out under the car." They said, "Oh, I have to check in first..." So, here I am digging them out, and I watched as two of the other security guys sit in their security car and watch me dig this person out. As soon as I got them free and they started driving away, they chased the car for a bit, then realizing they couldn't catch up, they swung around. They rolled the window down, and said "Oh, we were going to give them a ticket, and the other guy said, he just saved us 2 hours worth of paperwork!" I just rolled my eyes, and left.

I guess there are few "good Samaritans" left... or else people like to watch others suffer and get enjoyment out of it...

 

After we bought a boat, my wife bought one of those jump starters to use with the boat. I didn't need it because we kept the boat in the back yard and disconnected the battery when sitting and I charged the battery before using it. We rented a boat slip last summer and that meant keeping the battery connected to run the bilge pump. The float switch stuck and drained the battery. Afterwards i got the battery jump box out and tried to charge it. It wouldn't charge. It proclaimed 500 amps on the side of the jump box. I took it apart and found a 19 amp/hr motorcycle battery inside. So, I bought a regular battery for the boat to use as a backup jump starter. In my opinion, those jump starters are puny and a waste of money.

 

How well a jump box works depends on a number of variables. Cheap jump boxes generally don't work period. I own Snap-On jump box and we all own them at the marina I work at because they flat out work better. (They aren't cheap though.)

Second, if a battery is stone dead, it will kill just about any jump box - even mine.

BTW, some of the new Lithium Ion miniature jump boxes are flat out awesome!

 

Yeah, I saw one of those small lithium ion jumpers demonstrated on a boat and it was amazing. I'm thinking about getting one of those for my motorcycle tool kit.

 

A couple of guys at the marina have purchased them and they were pretty impressive in starting boats & jet skis. Actually, for jet skis, they're awesome because one doesn't have a lot of room to work in them.

But the thing that sold most of us was when our 12,000 lb. capacity diesel fork lift needed a jump on a 25 degree day. (And yes, it was pretty well dead.) We hooked the little jump box up and it fired that monster up after cranking it for probably 10 seconds. That's some power in a small package! I'll probably be buying one in the spring.

 

The small jump boxes became popular about 2 years ago, just about all of them have been going out recently in my shop. I keep one for emergencies in my truck, but I use one of my JNC jump boxes at work

If the battery is just low, just about any jump box will do the trick.
If the battery has a bad cell, it might take two big boxes to overcome it, or bypass the original battery and take it off the system to get it started, and then reintroduce it once the vehicle is running



To OP, sounds like your Alternator is on its last leg

 

That's exactly what we do at the marina. And we see more than our share of "stone dead" batteries.

 

Thanks for all the replies, folks! It died again on me last night. Took it to a shop and a bad alternator was confirmed.

Here's the thing - I can't afford to have this shop charge me a buttload for labor. I know a few basic things; brakes, oil changes, etc, but I've never replaced an alternator before. Figuring I could give it a shot. So I have two follow-up questions here.

1. Are there any recommended videos out there for how-tos on changing an alternator on a F-150? Anybody have any tips or words of warning?

2. On the off chance that I fail miserably and end up needing to take it to a shop, could I hypothetically just charge the battery up and drive it to the shop even if the old alternator is out? The point here is to not shell out more cash on a tow truck to get it where it needs to go.

Thanks again. Ya'll have been a great help.

 

It's really easy -- especially since you can fit a person inside of the engine bay of the V6.

1. Disconnect the battery.
2. Remove the accessory belt by using a 1/2" drive ratchet head on the auto tensioner.
3. Remove the alternator by removing the 3 bolts that hold it in. Disconnect the wiring.

Reverse the steps to put it back in.

I removed mine when I was diagnosing the squeaking noise it was making several years ago in about 15 minutes.

Hardest part is getting the belt back on... removing it is like nothing.

Edit: If you are strong man like I am, you don't need no stinkin' 1/2" drive ratchet to remove or put the belt on... you can use your hand and pull up on the auto tensioner.

 

Yes a vehicle *could* be driven a short distance without an alternator
You won't make it very far with the belt off, and the water pump not spinning

 

I bet you had your truck running while trying to jump the other car, right?

Reason I say that is every time I've done that, my alternator died a short time later... Every time! This was on various vehicles too..

Finally put it together and I'll jump a car, but I'll do 2 things first.. First, check the battery cables. Half the time, they are loose or corroded. Tighten them up/clean them up, car usually starts. Second, I shut my engine off, connect the cables and then have them start it from that.

I think what happens when you jump while your vehicle is running, is they pull so much power your alternator kicks in full bore and kills it somehow?

Dunno what really happens, but that's what's happened to me in the past..

Good luck!

Mitch