Alternator help. What amp do I need/have

so my 2013 5.7 needs a new alternator. Got it tested in the vehicle at autozone and they confirmed it.

Went inside to price them.

They have a 100, 130 and 150 amp?

I don’t run any crazy stereo systems or lights, yet.....

Is bigger always better? Can I survive with the 100?

 

Do you have cold weather option? Higher amp alternator.

 

They are interchangeable as far as how they bolt in. I don’t remember price difference but wasn’t that bad and nice to have biggin

 

I do not think I have the cold weather package.

Is there any easy way to tell? button inside on the dash or anything. I thought it was a heated windshield and wipers. I bought the truck used an the cold weather option never occurred to me

 

I think any of the trucks with the tow package have the 150, but I could be wrong. I will check, as I had asked in the OEM parts thread about a larger alternator.

 

https://www.tundras.com/threads/ultimate-oem-toyota-parts-thread.10707/page-70#post-1380644

This is to the Page with the alternator question. Post 2097, I think.

Edited for correct post number

 

The best way to tell is to register on the Toyota owners site. It will give you the build information, including the specific alternator that came on the truck.

This definitely doesn’t look like a job you want to do twice.

 

This was from when I registered my Tundra on the Toyota owners site.

 

I can attest it sucks to do. A 6 or 7 on a 10 scale.

 

@Rph74

thanks! I just registered but my information does not list alternator size, So I am assuming I have the 100amp because I do not have any of the packages that require the larger 150.

Now I just need to find one in stock.

Is it possible to over charge the battery or system? Will I hurt anything getting larger?

 

Dang, I was hoping it would be listed on there. I would think that you’re correct on it being 100a, hopefully someone can chime in on whether too high of an amp alternator is a problem or not.

I know too low doesn’t work, just don’t know about the other way around.

 

From my awesome google research, it says a higher will not damage anything, they are just more costly and sometimes (not in my case) physically larger. Im going to research a little more.

Thanks Tundra guys and gals!

I just need to find one in stock near by.

My buddy is swapping it for me tomorrow.

 

A larger rated alternator won't hurt anything.

 

Thanks everyone. Now knowing I can use any amperage available since my truck originally came with 100amps I just need to find a decent priced one with a lifetime warranty in stock

 

Nice dog by the way...

 

You probably only need the $15 brushes inside the alternator replaced. They're the usual wear item.

 

Sometimes the diodes fail too. Used to be able to get rebuild kits with brushes and diodes.

 

Good advice. If you elect to save $$$ by rebuilding, I would add that you should investigate bench testing the alternator before and after the rebuild: Do it before the rebuild to confirm the alternator definitely has the problem, then after to confirm that the rebuild fixed the problem. If it still has the problem, then you don't want to go that pain of reinstalling just to discover you still have a bad alternator.

 

Have the old alternator tested when you go in to buy the new one to make sure it's bad, then have the new one tested before you leave the store to make sure it's good. I've had a number of alternators (and a couple of starters) that were dead out of the box. A quick test saved me a lot of sweating and swearing. One store griped about testing a new alternator until the test showed it was bad. His attitude changed real quick.

 

How can you test an alternator out of the car?

 

A Toyota OE alternator is $300. The money you save by buying some random alternator from Auto Zone remanufactured by someone making $8.50 an hour in Mexico just isn't going to make up for doing the job twice, or worse having to pay a shop to replace it for you when you're away from home.

If you have the Tow/Haul button, you have the 150A alternator.
If you have the rear seat DVD but no Tow/Haul button, you have the 130A alternator (that has to be pretty uncommon!).
If you have neither, you have the 100A alternator.

 

All good parts houses have testers that will check both alternators and starters. They can check it before you buy it.

 

Would all factory tow packages have the tow/haul button?

 

From the Monroney sticker (window sticker):
COLD KIT $100.00
includes: HD battery, HD starter, HD anti corrosion protection,
windshield wiper de-icer w/timer

 

Anyone know if you just having the factory hitch means you do or don't have the tow package on a 2014?

 

To answer OP's question, "How many amps do I need?" the answer is, "ALL the amps."

 

When you say 150A Alternator, does ot put out 150 at idle or while you are driving?

 

That is what Toyota lists them at. I can't say how they measure them and at what RPM. It's 100, 130 or 150amp. My problem is I need to replace mine but don't know what size I have and it's not easy to see the part number while it's on the truck.

 

I would go to toyota parts and give them your vin

 

The established standards for alternators are to rate them at 6000 RPM. An alternator doesn't put out current, instead it supplies current where there is demand. So at 6000 RPM, a 150A alternator could supply 150A.