New Alternator Just Melted! Little help on a confusing issue, plz.

Hey guys, sorry for the long post, (my first on on this forum!) but this one is a good puzzle.

This issue has got me confused, and I could use a hand. Ive searched the forums, but I havent seen any similar sequences to this. If you could comment a link, to a similar situation, I'd appreciate it!

New owner of a 2006 Tundra DC 4x4 (3 weeks ago), and Im having some crazy electrical issues. I'll break it down step by step so you can see what happened.

1. 4 weeks ago, bought the truck. Ran fine, slight "bounce" or "dip" in the battery gauge, but no battery light, or check engine light, and gauge did not dip below lower 1/4 mark, and generally not for more than a second.

2. Looked at the battery and it looked OLLLLD and smaller than the stock one, so I went and tested it, (bad) and got a new AutoZone Gold (larger, and correctly sized) battery.

3. Installed battery with new terminals (old ones were pretty corroded)

4. Took roadtrip to the mountains for a week. 4x4, no problems (no rivers! no rocks! so I didnt drown/break anything!) Returned successful.

5. After a few days at home, the battery showed low voltage, battery light came on... and I could see that the alternator was giving out... so... I thought perhaps the guy sold me the truck knowing that the alternator was on the fritz, and just charged a crappy battery to get it off his plate, and let me 'discover' that the alternator was on the way out.

6. I let the battery sit on the charger overnight (65% up to 100%) Then the next day, I went to AutoZone and the new battery tested OK, however, the Voltage Regulator on the Alt showed FAIL, so got another rebuilt 130A alternator. $220 USD (inline with what I had suspected all along about the old alternator.) So far so good.

7. Went home and installed the new alternator. Removed the water pump from the bracket for access, and swapped the alternators. Put it back together but got a funny constant whine on the Power Steering Pump after re-install. Yes, I checked the routing of the belt, and the tensioner feels like it has OK bearings. I thought perhaps it was just a bubble in the hydraulic line that needed to be run out.

8. The Melt Down: Drove to the store, smelled burning rubber, realized that the belt was getting hot, alternator was not providing power. I thought perhaps it was just the belt slipping or that somehow I stretched it or screwed up the install? So I stopped by the store to get another belt, came home and parked the car.

9. Later that evening, I went out to swap the belt (its cooler in the evening) and found the battery completely drained (0v) and the alternator SUPER hot (several hours after parking), and I can see that the alternator is charred by looking into the front of the air slots.

It appears that the alternator failed, (over stressed from bad new battery?) and internally shorted out, drew down my entire battery and now both the new alternator and the new battery are both DEAD. (sitting on a burnt up belt)

Here's what Im thinking:

Original Battery was trash.
Original alternator was intermittent and needed to be replaced anyway.
Swapped for new battery.
New battery got hammered by the old alternator failure, and caused a bad cell.
Went to check it and got an alternator failure, so swapped it.
That bad cell in the battery (damage from the old alt) forced the new alt to run super hard and melted.
Internal short in the alt drained the rest of the battery in the evening, and here we have it.

(I think?)

Im not sure what the sequence would be for this...

Bad battery causes overdraw on new alternator, freezes belt, and shorts out?

Now I have a dead flat battery (not recoverable), a melted alternator, and a smoked to hell belt. I cant start it or drive it. At least its across the street from my house, so I can fix it after you all HELP!!!

Any feedback or thoughts on why/how this happened? Sequence of events or collateral damage? Is it something I did on accident? What are some practical steps to check?

Any feedback is appreciated.
What would you do?

Thanks in advance.

-Dustin-

 

That whine is your Alt. The rubber smell was the belt locking up. (Bearing). Find a better brand of rebuild or buy a new one. You could try to slow charge the battery if it's not maintenance free make sure the plates are covered. Double check your belt routing around the waterpump. The parts house guy might help with a new belt since his alt is the reason it smoked it. Talk to the MGR

 

I'd give it 95% your reman alternator was bad out of the box. I've never had a parts store reman last longer than a month.

When you get another make them test it before you leave the store.

 

I’d try a Denso Reman’d Alternator straight from Denso. Denso will link you over to online sellers for the best pricing.

https://densoautoparts.com/


I just looked and Denso online is showing unavailable on the 130 Amp Alternator. This is rare! You may need to go through online stealership for a reman. Usually good pricing from them on a reman which is Denso anyways.


Check your main grounds on your engine. One at the back firewall (pass side) and another next to your battery attached to adjacent quarter panel.

 

It sucks that you've got to go in twice and redo it, but you may want to consider (while you're in there) replacing the water pump and timing belt. Unless of course the belt was recently changed. Make sure to completely clean the mating surfaces of the water pump/block. The last thing you need is a coolant leak from repeated removal of the pump.

 

Oh, and welcome to the club!

 

Sounds like a poor alternator rebuild. I’d get a Denso and put it in.


Do a parasitic draw test too when the new Alts in. Plenty of YouTube videos on how. This will tell you if you have something draining your battery

 

Thanks a MILLION for the fast reply guys!!! Im amazed and humbled by your fast responses to my issue.
Been up all night thinking about it, and you are right: I'll go back and swap the alternator for a new one, and then make them up for the battery (new Duralast with warranty) and the belt I just bought because the alternator burned it up.

I'll keep you posted for the results, and THANKS AGAIN for all the warm support. Damn, Ive never felt such a great community online before, and I must say, I'll be learning and helping others as time goes on. You've inspired me.

-D-

 

Just an fyi stevinson toyota west has great online prices and no shipping. You do have to order online though and it will take a few days to process the order, so not good for things you need immediately.

 

OK! Update time.
Got up this morning and being thoroughly inspired by your posts, I went out and pulled the fried alt, and went straight to the local AutoZone (yes I know... meh) and had them warranty the alt, the battery AND the belt.
Pretty amazing customer service at the location (96th and Federal in Westminster Colorado for those nearby) and I got out of there with a receipt and fresh materials.

Re-installed alt, battery and belt. (I think I could do it blind now, thanks to two "in and outs" in the last 48 hours.) SUCCESS.

No suspicious "whine" like before, voltage right at dead center, and very little response when accelerating and returning to idle. No dips or odd drops like before.

Now, I did notice that the ground to the back of the engine compartment (The one that Hand Model pointed out) has been previously "fixed" (read: suspicious).
Im attaching a photo for your thoughts. I did a continuity test, and it seems fine, but I know that it could build a charge under load and resistance could appear when Im running the car on the highway.
(Forcing the ground to come back around to the battery ground.)
Any thoughts on replacing that one, and: With what? Can I make my own, or does it need to be something specific? Recommendations? Im happy to just replace it to be sure.

Speaking of the battery ground, I pulled it, cleaned it, filed the paint down and reconnected it.... just to be sure.

Now, Im on to the Parasitic Draw test!

Again, very grateful for your responses, and big high fives to each and every one of you. Im taking your advice to heart, and of course, learning along the way.

-D-

 

Just a little Colorado Tundra porn for you all.

 

I'd definitely replace the ground at the back of the engine that attaches to the firewall. I cannot imagine any issues with just getting a cable from your local auto parts store that is the same length. I'd actually go up a size or two in gauge.

 

Ive got some big ass cables I'll swap it out. Does it need to be a particular type?
Braided copper? Solid Copper?
Stainless steel? Mesh?

Anyone know the correct gauge, or how many amps its drawing? I can do the math to size it with the material.

Thanks!
-D-

 

I don't think you can oversize a ground wire. For wire type as long as it's real copper and not that copper plated tin stuff you should be fine. That tape job is terrifying but those landscapes are amazing.

 

I always assumed you could oversize the ground wire.

 

Welding wire works great for any kind of cable.

 

A braided #10 with star washers under the crimped ends will ground it.

 

I mean you can never go too big. People do wiring upgrades throwing on zero gauge all the time without issue.

Reading my sentence again I see how that could be taken either way.

 

Upgrading the wire for the engine ground won’t hurt or anything. That ground is literally there just for all the Low voltage sensors to reference ground on the engine

 

Yep. Also keeps the transient energy from traveling (grounding) into your wheel bearings and transmission and messing them up (via battery side). Good grounds make the trucks entire electrical system optimized.

 

One of the biggest and greatest upgrades to any truck is the big 3. Seriously. The voltage stability and all around happiness of the electrical system will make everything last longer (thanks to less voltage fluctuation)

 

I’ve cleaned up all my grounds pretty good over the last 2 years and used electrical grease on the end braids. Think I’m going to fab up some new additional ground wires and sister them up to the ones on the firewall and the one at the battery. I’ll do the same at the alternator when that time comes for replacing soon.

 

I dunno, I got some leftover 500 MCM from a job....

 

Yep I've had this happen twice..

 

I would like to jump into the conversation as well. I recently just replaced my battery, alternator, and belt in my 2001 tundra. Worried my tensioner is not tight enough but dont know how to accurately test it. Spins free no play in the pully or anything. Is there a torque spec I could use on the tensioner to see if it is applying enough tension?