3rd Gen Alternator Recommendations

I have an AGM, battery and have the known alternator challenges (like everyone else) with slow drain or alternator not charging optimally. There is a great post by @crashnburn80 HERE that talks through all this and some fixes if you have certain year models. I have the new NOCO Genius 10 and have it on a trickle charge most of the time but that is a little ridiculous. My OEM alternator just isn't optimized for AGM. I have OVTune and also vF tuner which will allow some adjustment to the alternator output to meet float/charge levels but this is not finalized yet and a WIP.

My question is, since I have a 2017 3rd gen, can I just upgrade the alternator? and to what models. I have found Nations Starter Alternator, DC Power Engineering, Mechman, Quality Power (Not 2016+) and Singer Alternators but not sure on quality and specifics on below questions.

1. Plug-N-Play compatibility - OEM Fitment.
   
2. Optimal Amperage to get (270 amp vs 370 amp)
3. Do I need to upgrade wiring?

Any help would be appreciated -

 

Upgrading the alternator will not solve the voltage issue. Upgrade alternators provide more Amp capability to supply larger electrical loads, but it still does so at the voltage specified by the ECU. In the case of running an AGM, that voltage spec from the ECU is too low and changing the alternator does not solve it. You need the ECU tune to adjust the charge voltage in 3rd Gen. Heavy duty alternators can be a great upgrade if you are constantly winching or have other very high electrical loads exceeding the capability of your alternator, but for most are not necessary. Keep in mind your battery is effectively a power reserve, so by having a higher capacity battery you have a larger power reserve to buffer from the alternators ability to keep up for intermittent high power demands. Also the TRD/tow package trucks came with Toyotas higher output alternator (130A I believe) vs the lower output alternator of the lower trim levels. If you had an a non-tow package truck, I'd consider upgrading to an OEM 130A alternator as a more reliable upgrade than going to an aftermarket high output alternator, assuming you didn't need the extreme output level.

Edit: Also you shouldn't need to keep your truck on a trickle charger. Regular wall charge intervals such as once monthly should be sufficient to keep battery sufation at bay.

 

@crashnburn80 - This is awesome info and good advice! Thanks! I do have the TRD PRO with the higher 130A so I should be good so maybe there is a parasitic draw somewhere. I will do the OVTune hack which gives me 0.05 increase increments that I can play with that should get me where i need to be.

Keep up the great work!

 

I'd recommend getting a +0.5v bump to start. That seems to be the optimal increase. Keep in mind voltage will fluctuate a lot, depending on the charge state of the battery and electrical demands of the vehicle, so looking at the voltage at a single point in time is not sufficient. You'll typically see the highest voltage after your truck has sat for an extended period of time and immediately after starting the truck as it replenishes the draw used by the starter.

 

ok - I see OVTune has some more conversation with forum users on vF software edits around the +0.5v

https://www.tacomaworld.com/threads/vf-tuner-for-the-3-5l-tacoma.662948/page-67#post-23499159

We just need them to bake this into the new 2.0 final versions and I think we are good to go!

 

I added some LED lights to my truck:

Diode dynamics 42" flood bar - 11 Amps
Diode dynamics 30" driving bar plus two KC Pro6 driving lights - 13.1 Amps

Those are actual measurements I made with a DC clamp meter. Those two loads are not too likely to be on together, but they could be.

Pretty sure my truck has the 130 A alternator. Do you think I can run with the stock alternator, or do I need to upgrade it. (Please say no)

 

So you are at +24.1 Amps over stock with everything on. I believe the non-tow package trucks come with a 100 Amp alternator, your tow package alternator has an extra 30 Amps easily covering your additional power needs. So no need to upgrade.

 

The 270 amp DC Power Inc alternator is missing the two attachment points on the side to hold the plastic box that has the cables coming from the output (+). Also, the LIN plug faces outward instead of toward the rear like the Denso alternator. This doesn't sound like much, but there is little play in that wire and plug. It will need a couple more inches to turn the corner and get plugged into the side of the alternator. The wire that goes to that plug is [firmly] attached to a bracket on the engine that isn't easy to get to. The two bolts on that bracket aren't easy to get to either. They're both 12mm heads and seem like you're reaching a quarter way under the engine just to get to them, but cannot see them while you're fumbling around in a tight spot with almost no room to swing the ratchet, even if you get the socket onto the head of one of these two bolts. One bolt goes forward through the bracket into the back bottom part of the alternator, the other holds the bracket to the engine block. It's very tight. If you have very long skinny arms, it might seem easier.
The new DC Power Inc 270 amp alternator will not use that bracket, nor will it have any rear attaching hardware on it. It's held in place strictly by two bolts (they provide) into the front of the alternator. There is no rear pork chop on the top either. It's completely missing.
I called DC Power Inc, and they told me that I just have to find a way to attach that box (the one that attaches to the side of the Denso alternator via two bolts) to something else. I can't see a way to attach it to anything without significant engineering and creativity.
Last, but certainly not least: If you have a 130 amp alternator, your 'Alt' fuse (bolted in fuse inside the fuse box) is rated at 140 amps. If you install this high output alternator, you will be forced to add a thicker battery cable outside that, and fuse that separately if you want to go beyond 140 amps. This is absolutely an absolute crucial show stopper, if for some reason the output exceeds 140 amps. I mean, that is what you bought the heavy duty high output alternator for anyway, so it would be beyond foolish and myopic not to install large gauge cable from the output to the battery to avoid blowing that 140 amp fuse.

 

Nations Starter Alternator resells DC Power Engineering alternators. The others besides DC Power Engineering, only offer gen 2 or before alternators.

 

Makes me wonder what alternator fuse (Alt Fuse) is in the fuse box on a Tacoma with a 100 amp alternator. If someone swaps out for the 130 amp alternator, will they need to do a big 3 + bypass in order to prevent blowing their fuse; or can they just unbolt the lower amperage fuse and put in a 140 amp (like what is in a tow package Tacoma).

 

If you put in the 130A tow package alternator, you can just swap the fuse in the factory fusebox. Sourcing anything higher than 140A in that fuse form factor is hens' teeth - the only options are custom work or a separately fused bypass cable from the alternator.

 

I have the DC Engineering 370A alternator for my 2022 tacoma installed a few days ago and im having issues. I ran the big 3 kit, but im not getting a 14v output. 13.1v is the highest i get when driving and it goes to 12.8V when idling. I have the big wire on the positive stud first than factory positive lead. I dont have any idea what could be causing this. Do i need to add a ground cable from the engine block to frame? I already have a 0 gauge wire going to chassis ground from battery negative. Maybe thats an issue?

 

Did you ever get this sorted? I’m thinking of going the same route with the DC Power Alternator. But all the wiring obviously has to be upgraded. At least ,that’s my thought.

 

You'll need to tune your truck and adjust the ECU to accomplish a 14V+ output, you wont be able to change the voltage by just swapping out the alternator.

 

Yea i got a KDMAXpro+ tune. It kinda fixed it but still get low voltage only when idling. When driving, its fine. Now ive been working on my audio so far. Truck drives far better with the tune. I say its worth the tune not just for the voltage but for driving.

 

So with the tune do you still need a upgraded alternator to properly recharge a AGM battery?

 

No. You can stay with the stock alternator. I only upgraded due to my electrical needs. I didnt want to use the stock alternator because i need more than it can provide.

 

But if I run light bars and the winch occasionally on a agm … say a yellowtop the stock alternator without the mod/hacks would charge it sufficiently?

 

If they're LED light bars, certainly. If you're winching for extended periods without time to recharge, you might want to, but even with a ~350A draw from my winch I've never run into a situation where recovery drained my battery (slightly larger than stock Duralast Gold) sufficiently to warrant worrying about it. If you are draining a battery with your winching, a better bet would likely be a second battery.

 

Did you just leave the wire box that attached to the Denso alternator just hanging? How did you solve the problem of the LIN plug on the outside of the 270amp DC Power Engineering alternator? How long did it take you to replace it (start to finish and running Tacoma)
Your low voltage problem will require a tune that addresses that specifically, or in addition to all the other tweaks it provides. Thank you