Alternator not charging battery, Possible bad wire connecting to the fuse box the culprit?

Hi guys, I have a 2008 4cyl 4x4 Tacoma and recently the battery light went on. I had the alternator checked while on the truck at Autozone and they said it had a bad voltage regulator so I replaced the alternator but it still had the battery light. I had the new alternator checked while on the truck again and it still showed a bad voltage regulator while the testing machine was attached to the battery terminal. Then they connected the machine to the bolt on top of the positive battery terminal and it got now reading at all leading to belive something was wrong with the connection of the wire going from the fuse box to the top of the battery terminal.

I took off that top bolt and cleaned it very well and still got a battery light, then I took off the negative battery ground wire and cleaned it very well and at the same time also took off the top of the fuse box housing and noticed that the wire leading from the alternator into the fuse box looked a bit strange. There were some frayed wires and what looked like a drop of solder at the end of the wire where it connects to the metal arm. Is it normal for this to have solder on it or have the wires melted? The wire itself looks very worn and brittle, I wiggled it around a bit and got a small spark from the wire. I then started the truck and the battery light went off and has been fine for a few days but the battery light just came back on.

Do you think this wire is the culprit? Does anyone know what the metal arm part is called so I can order a new one and cut the end off the wire, restrip it and connect it to the new arm for a good connection? I had the old alternator tested off the truck and it tested fine so the alternator is not the problem. Thanks so much!

 

Looks like your on to something in reference to your problem?

Not an expert here just a suggestion.


NOTE: Care and caution should be taken when working around electrical items, don't want to short out anything during this process.

1.) First I would disconnect the battery and either remove it from the engine bay or isolate the battery terminals from the connectors. (also clean both terminals on the battery as well as both connectors that connect to the positive and negative terminals.)

2.) After the battery is disconnected or removed, I would disconnect that specific wire/cable that you point out in the picture you posted and fully inspect and clean the wire/cable and the whole area associated with it's connection. Making sure the wire/cable is secure and with a tight connection on both ends (to the fuse box and the alternator).

3.) Or if possible, disconnect that specific wire also from the alternator and remove it and replace it with a new one (from Autozone, O'Reilly's, etc.)



4.) Once all that is done, reconnect everything back, with the battery being the last and apply some sort of electrical contact grease to all connector points (both battery terminals & connectors as well as both connector sides of that specific wire/cable) and give it a shot and see what happens?


Hopefully that would solve your problem? If not, well the only $ lost would be what you paid for on that specific wire/cable and the electrical contact grease.

Good Luck and hopefully everything works out for you and getting that problem solved.

 

It looks as though someone over the years might have mucked that up, or it overheated and they tried (poorly) to solder it--here's what it should look like (my '09):



It should be crimped, and soldered too perhaps, but that's not necessary if properly crimped with a proper tool.

To fix it you will of course have to get a new terminal (any FLAPS should have that) and a .

Cut that thing off, strip the wire and see if you can get back to unburned, clean wire, then install the new terminal.

 

I bought the hydraulic crimper I have from HF 6 or 7 years ago, it was $20 on sale IIRC. In poking around the web just now I found that Walmart offers the same tool for $30 with free shipping:



I found a few sellers on eBay also, as low as $24 with free shipping, however I'd rather pay a bit more and get it through Walmart's online site. It is not "sold or shipped" by Walmart but they hold the vendors they list accountable as does Amazon...

 

Same symptoms my truck had but the nut was just loose in the fuse box. Would say that wire is your problem

 

If I may,

You are on the right track with the electrical. opposed to try to fix the wire, it would be better to replace the cable it its entirety, or at least as much as you can.

also replace the ground cable.

it is a 2008, there is a good probability the cables are "worn out"

it has been my experience that generator to battery, battery to starter, and battery ground to chassis ground are 90 percent of the electrical problems found in vehicles. No one bothers to replace these cables until there is a problem and no one EVER checks them during services.

clean all point of contact also.

 

I agree--from the photos it appears your truck has led a hard life--this would be the best repair...

 

One word you said tells me the issue. Spark. If you wiggle the wire and you get a spark, you need to either repair it PROPERLY or replace it. Looking at the half assed crimp job and corrosion in the wire, Id suggest getting a new one.

 

Agree with @windsor . You see a spark, that is an area that needs fixing ASAP. May not be THE problem, but it is A problem. A temp fix is to crimp that wire with whatever tool you have handy until you can replace it. That should prevent further sparking, but because of the corrosion, the connection will have too much resistance that could lead to a hot spot, that could lead to burnt wire.

 

Thank you everyone for the very detailed replies!! Really appreciate the help

I am going to replace the metal arm and restrip the wire (after inspecting the rest of the wire) and properly crimp it with the tool mentioned here. Will post back with its success. Thanks again!

 

Yea, it might have been soldered, or I think more likely it was arcing and welded itself.

 

Replaced the connector on the wire going into fuse box and everything has been good for the past week.
So if you think your alternator is going out be sure to check this wire. Thanks for the help everyone, you rock!!

 

What Tex-Tac said about grease is also spot-on. A little grease keeps the oxygen in the air from "Oxidizing"//corroding the connection in the future. While you have everything all cleaned up also use on your battery terminals for same reason. Oxygen is great for breathing but has interesting affects on everything else.