Need wiring help for Alternator

I've got a 2010 Tacoma, 6-cyl., 4WD and last week my alternator decided to die on me. I got the replacement one in last night.

In the process of removing the old alternator, when I was removing the plastic cap that covers the large main wire (not the 3-pin connector), the wire rusted away from whatever crimp connector was attached onto the stud of the alternator.

The wire itself looks fine since it was all still sealed, but just the crimped lug (or ring terminal, not sure what they're actually called) has broken away (see pic below).

I have been searching all morning for a replacement lug connector but cannot seem to find much. I can't find any type of pigtail style harness as a replacement. I have found a few options of lug/ring style crimp connectors for the approximate wire size (I'm guessing based on the strand diameter that it is either 1, 1/0, or 2/0 awg), but none of them in this wire size come in anything smaller than a 3/8" stud hole. The stud I've measured on the alternator is 1/4".

I have seen the big3/big6 wiring upgrades, but I would just like to keep this as stock as I can. It an OEM Denso alternator and I don't run any addition upgrades that call for more electrical load.

Can I use one with a 3/8" stud hole as long as I get a solid connection between the connector and the alternator? Are there any other things I can do to get this back together?

 

I don’t believe the wire is that large a gauge. I’ve seen people when discussing wiring upgrades say it’s roughly 4awg or so. Which there are 4awg ring terminals with 1/4” stud holes. You want the ring terminal to have the correct hole and not be a loose fit for something like an alternator.

 

Okay, I guess I'll try to look more into what gauge wire that is first. I was basing it off a rough measurement of the broken crimp connector.

 

Yup, Im guessing #2 awg.

You need to measure the copper wire itself, not the overall insulation. Or you can take the 9.03mm measurement minus 2x the thickness of the insulation. Then search to find the nearest AWG size matching that diameter wire.

If it were me Id find a tinned uninsulated ring terminal (correct size stud and wire gauge) at a local hardware store, some good adhesive lined heat shrink, and a cheap hydraulic crimper to make the repair.

 

Measuring the sheath on the wire is not all that helpful. Wire gauge is determined by the wire inside - not the outer sheath. Different types and brands of cable will vary greatly in how thick that material is. In all honestly, even the inside wire diameter will vary a lot from brand to brand. Cheaper wire will cut corners on that kinda thing.

Plus, at the point you're measuring the wire is not round. The terminal crimp has turned it oval and you're measuring the long dimension of that oval. You're gonna have to cut that old terminal off and strip the wire back anyway so might as well do that now and you can get yourself a better measurement.

That is DEFINITELY not 1, 1/0 or 2/0 wire. Check out the pics here comparing 8ga up to 2/0: https://www.diymobileaudio.com/threads/welding-wire-comparison-pics.425130/

I'm pretty sure that wire is ~8ga. People usually go up to 4ga when they upgrade. 4ga from the factory in any automobile is just about unheard of. I'm sure it exists on some big heavy duty vehicles and electric cars probably have some big wires but I've never seen bigger than 8-10ga on any normal car I've ever worked on.

There will be plenty of 8a lugs with 1/4" hole. The world is your oyster as they say. But I'd still be prepared to modify it. Once your lug arrives be sure to test fit it before crimping. In my experience, you often need to trim generic lugs to fit specific applications like alternators and fuse boxes.

 

I would be wondering if the corroded lug was responsible for showing a failed alternator. Did you have it tested?

 

#2 will handle 115 amps. You need that much? Have you asked the Alternator and the wiring? The lug can be removed and a new one crimped on.

 

I tested the alternator right at the stud last week when I first had the truck die and the alternator was completed shot.
I think the wire/lug that is now broken was maybe just holding on by a thread last week.

 

The alternator is rated for 130 amps, I wouldn't want to put anything on that would become a weak point so to speak.

 

I ended up picking up a 4 gauge, 1/4" stud lug connector on my way home from work and that seemed to be the correct size for the wire that was broken

 

Put the micrometer away. It is nowhere near this complicated.

Strip the black wire sheathing back about 2 cm (~1 inch) from the break. Exposing all the copper wiring strands inside. Twist all the copper strands into one clean bundle. Trim the frayed ends to length so you have ~ 1 cm / ~1/2 inch of clean twisted wire. You are now ready to attach a new eyelet.

Crimp an ordinary eyelet on, like shown below, that is the correct size. These are like 25 cents each at ACE Hardware. $2 if you you have to buy an 8 pack bundle. Bring the original for comparison.

Solder it. Optional, but highly recommended step.



Once you have managed to attach an eyelet, assuming you have planned ahead, now is when you slide the heat shrink tubing down until it is over the crimped and soldered eyelet. Heat shrink that. And you will have a re-purposed wiring harness eyelet connection that will last for years.

It should look like this when you are done. May not be to scale.

 

I do this often. Post 11 is all good info.

You don’t have to have the correct tools. Heck I used to just bash it with a hammer to crimp. Now I use 2 made by ezred. I use a paint marker to help clock the cable correctly to the lug so the cable isn’t twisted. Crimp AND solder is good. Solder only, I’ve had them fail, sometimes things get hot enough to have it separate. The heat shrink with the glue inside is nice. The glue less will work. When you’re done, if you soldered with flux, blast it with brake cleaner to clean the flux off before putting on the heat shrink. It’s probably far away enough from the battery, but I’ve had it get weird with acid.

$26 EZRED B790C Hammer Indent Crimping Tool, Crimps 8 gauge to 4/0 AWG

https://www.amazon.com/Z-Red-B790C-Hammer-Crimper/dp/B000M7LFKK

$70 EZRED B7946 3-Point Mini Wire & Cable Crimper

https://www.amazon.com/E-Z-Red-B7946-Crimper/dp/B00CT9M4FE

I think the more expensive one is more than a hydraulic crimper from harbor freight someone I work with has.

 

Thanks, I get the steps on how to attach an eyelet. My issue was that the original eyelet was completed rusted away so there was nothing to base any comparison on. My closest hardware/electrical store is an hour away so I was trying to figure out what size I needed so I wasn't taking a bunch of trips on my bike to get different sized eyelets.

I guess it's beneficial to have a high-watt soldering iron to be soldering these eyelets onto a 4awg wire? With such a large wire it'd really take a lot of energy to heat it up enough, or are there any tricks to soldering with any general use soldering iron?

 

I picked one of the hammer crimpers up from princess auto today on sale for $10. Are there any tricks to soldering large gauge wires with a general use soldering iron, or is it not much use to try if the heat dissipates too quickly? Should I be fine with just a solid crimped connection and no soldering?

 

Soldering - A 100W iron should work fine, just make sure you use a "broad" tip as opposed to a "point" tip use for electronic component soldering.

 

A properly crimped connection does not need solder.

 

This is probably the harbor freight one I was thinking of.

 

You don’t have to solder it. But it’s a good excuse to buy one of those trigger bottle mapp gas torches. They work great for killing spiders.

https://www.homedepot.com/pep/Bernz...MI4uiX79SrjwMVpw5ECB3FmBEQEAQYASABEgIk__D_BwE

 

For automotive purposes you probably shouldn't solder it. It needs to flex a bit to absorb vibration.

 

For marine alternators a crimp terminal or is the way to go. The problems with soldering are:

• Solder makes the wire brittle, and the embrittled soldered wire is more prone to crack from vibration.
• Solder can wick up into the wire under the sheath and make the wire brittle - more prone to break unless it is supported past the soldered connection.
• Solder does not bond to dirty, oily or corroded wire. Cleaning the wire in situ would be almost impossible.
• Solder may contain flux (acid). Most people don't properly clean the flux after soldering.

I believe that the alternator wire is AWG 6 (which is really too low for 130A, but the wire length is VERY short, and nobody is pulling 130A continuously). See this thread for PIX and routing of this (and other) wire https://www.tacomaworld.com/threads...-2nd-gen-tacoma-writeup-with-pictures.664674/

This pic (not mine) shows the positive wire that runs from the alternator to the fuse box;

The OEM wire is that lone skinny black one at the top of the pic.

I seriously doubt that anyone with a stock Tacoma has ever melted this wire.