I plan on taking it out and having it bench tested after work today but I've already read that you can get false readings even on the bench test so based on responses here, I may just get a new one...

Sorry this is going to be a long write-up but I want to give as much detail as possible because the electrical system is my kryptonite!!!

My truck hesitated just a bit when I started it yesterday evening, just enough to make me wonder if my battery was dying. I drove it a few miles meet up with a group of friends for a trail run and it was parked for about an hour. When got back and went to leave, I had the familiar clicking of the solenoid that you would typically get when a battery is dead or dying. One of my friends gave me a jump and it started right away but while I was coiling my cables up to put them away, it died again. We jumped it again and it started right away and actually ran fine for about 3-4 miles. While creeping up to a stop light I started hearing a noise that almost sounded like something was grinding or arching (almost like a welding rod burning) and then in a matter of 5-10 seconds my interior lights went dim, the ABS light came on, the airbag light came on, and then all the interior lights went completely out. When these things started happening, I reached back and grabbed my scanner and plugged it in so I could try to see if it was throwing a code. All of this was happening really fast and while I was on a very busy street so I turned off and onto a side street within a few hundred feet and pulled over. Luckily for me, I ended up a few doors down from my best friends house. So, I walked to his house and borrowed one of his cars to jump my truck again (I was just trying to get it another 3 miles to my house). When got back to my truck, about ten minutes later, I noticed that my headlights were on, very dim but on. I thought that was strange since my keys were in my pocket and I had been gone for at least ten minutes... When I got out of his car to pop my hood, I heard a clicking sound coming from under my hood and also from behind my rear driver door, which I now assume were my injectors and my fuel pump (again, my keys were in my pocket). So, I got in and put my foot on the brake so I could see if by chance the truck would start and the clicking stopped. I thought that was odd so I did it a couple more times and every time I put my foot on the brake the clicking would stop and then start again when I released it. I then jumped the truck a couple more times but it would die within a minute or two of disconnecting the jumper cables. So I just disconnected the battery and went home to do some research (It was already after 8:00 PM and I was in dire need of food and a shower after my run! lol).

All of the symptoms except the truck having power when the keys weren't in would have made me jump right to the alternator being bad but the lights being on and the clicking when the keys were in has me stumped! And then the clicking going away when I put my foot on the brake (with the key in the ignition) adds more confusion.

What say you?

 

I would start with the alternator, and also fully charge the battery(low amp and for a few hours) and have it checked. For the goofy stuff happening Id think the battery is so far drained that the truck didnt know how to act and maybe the constant jump starts hurt the computers in the truck...maybe but unlikely. Pressing the brake was probably just pulling the juice low enough to stop all other thing from going wonky and when let off the power returned. Test or replace the alt, charge and test battery then go from there. When my wifes battery died..2004 Gran Prix..(I knew it was battery, she started it several times earlier then went to leave and it was dead).....she had keys in her hand and doors shut, the open door chime going, speakers back feeding, and security light flashing yellow.....so I know a low battery can cause some weird stuff. Hope this helps.

 

Is this an 04 Heritage by chance or new body style?

 

2004 FX4 new body

 

Ok, then I would do as previously stated, charge battery, get alternator checked, battery checked, and check and clean all the grounds you can find. That should be a good starting point.

 

You can do a basic test of the alternator yourself with a multi meter. Should be putting out 13.4-13.6 Volts at idle.

Battery should have a min of 12.4 with the truck off.

Im pretty certain it's your alternator. Mine did the same type of thing when it failed. As who knos stated, the lights being on and the other anomalies were due to low voltage from the battery. I don't understand exactly to explain it but it is weird.

The grinding noise you heard, assuming it's a 4x4, would be your IWE's engaging due to the vacuum pump shutting off when the truck died. Should've heard mine while doing 75mph!!!.

You can replace the brushes in the alt if it's just low voltage output for about $7. If you do replace the alt. make SURE it's an OEM or you'll probably have other issues.

 

He can test it you are correct, but that only tests the output, not the regulator and other components in the alt and by the time you waste the time replacing what is bad and another part fails there is more time and money invested than just replacing, great suggestion but I would remove and have it tested and when told it bad just replace it. I wouldnt go OEM on the alt as most places offer a new or rebuilt with a lifetime warranty for less money, and its super easy to change. Hes not wrong but not worth the extra cash in this situation.

 

Just checking in to see if there was any more advice before I go replace the alternator. I had already ordered a reman from the stealership before I read this and got the oem for $169 (gotta love the local love for military -retired in my case!)

I'll report back once everything is running again, thanks guys

 

Not a bad price Im shocked really, what is the warranty on it? And did you test the old one first?

 

A common issue with these alternators isn't them failing, it's inadequate voltage output. This is most commonly caused by the brushes wearing out and the tolerances won't allow for proper voltage generation.

Some folks may not have the funds to immediately replace, of course, new is better (usually). I replaced the brushes in mine almost 3 years ago for $7, no issues, 14.2 volts at RPM, 13.5-7 at idle, running lights, trailer lights, 2 amps and stereo.

It's an option, an option which most folks may not be aware of, as everyone knows you can go to the auto store and purchase a new (reman) one. So, in MY OPINION, if the bearings seem good, no noise, play, and the pulley is in decent shape, the 30 mins it to me to pull off, fix, and replace, 3 years later, doesn't seem like a poor choice.

I ask this, at this point, what would I have gained purchasing a new one? Would it be completely unusual for a reman to fail after the same 3 years?

Just stating my case as you seemed so eager to completely dismiss the option as though it would be a foolish decision.

And if I were to replace, I would ABSOLUTELY go OEM be it new or reman. There's way too much information on this site, and on the web about how these trucks in particular, do not like aftermarket alternators.

I was not saying OEM was better and aftermarket was junk. I was trying to let the gentleman know that it's important, for piece of mind if no other reason, to go with OEM due to all the issues folks have had over the years with aftermarket alternators.

It's not worth the extra cash to purchase an OEM product, with all of the information available to make an educated decision on the purchase? Yet, it's worth all the money spent on an aftermarket v/s spending $7 on a set of brushes for a unit you already know, when functioning properly, is compatible with your vehicle?

IDK man, just my 2cents. Just please don't discredit someone who simply offers a choice to someone looking for options and information as though it really isn't an option without first knowing the facts behind the statement.

I digress and am not looking for debate, just thought you might could have......possibly......not be so "abrasive" when addressing others statements.

Thanks