Tundra Alternator

For the record it takes an awful lot of accessories to be on at one time with the engine running to exceed 100a pushing out of the Alt, and 5 seconds at 110a isn’t going to blow a 100a slow blow fuse.


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For the record it takes an awful lot of accessories to be on at one time with the engine running to exceed 100a pushing out of the Alt, and 5 seconds at 110a isn’t going to blow a 100a slow blow fuse.


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Very True... You ever try to change one of those 100amp or 120 amp fuses? It took us quite a long time to get it removed when we pulled the body harness out of the parts mobile. :(
 
Very True... You ever try to change one of those 100amp or 120 amp fuses? It took us quite a long time to get it removed when we pulled the body harness out of the parts mobile. :(


I accidentally blew mine because I didn’t have the battery disconnected. I had a fuse from my cummins. They are a tight fit


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Would upgrading to one of these alternators help prevent voltage drop when I have the A/C and headlights turned on? It usually goes down to about 12.8 VLT for me when both are on. If I cut off the headlights but leave the A/C on, it usually hovers around 13.0-13.2. This is while sitting at lights, idling.


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Would upgrading to one of these alternators help prevent voltage drop when I have the A/C and headlights turned on? It usually goes down to about 12.8 VLT for me when both are on. If I cut off the headlights but leave the A/C on, it usually hovers around 13.0-13.2. This is while sitting at lights, idling.
12.8V is not DISCHARGING the battery, so at least from that perspective, you aren't causing problems. Even 13.0-13.2V isn't charging the battery much if anything. Is that voltage directly from the battery or somewhere else in the system? There may be other voltage drops and the battery isn't doing so bad.

First step though (from a reliability standpoint) is to check/verify all high current connections between the battery and alternator. If you are loosing power there, all the vehicle systems will suffer (including working the alt harder than it needs to be).

-Charlie
 
12.8V is not DISCHARGING the battery, so at least from that perspective, you aren't causing problems. Even 13.0-13.2V isn't charging the battery much if anything. Is that voltage directly from the battery or somewhere else in the system? There may be other voltage drops and the battery isn't doing so bad.

First step though (from a reliability standpoint) is to check/verify all high current connections between the battery and alternator. If you are loosing power there, all the vehicle systems will suffer (including working the alt harder than it needs to be).

-Charlie


That voltage reading is from my ScanGauge tool. So I’m not sure if it’s reading the battery or the alt. The battery is still relatively new (7/21) and the alt is a Denso reman unit installed 8/21. So those two items should check out. I just never understood what caused that to happen. Or is it normal?

I’ll do some digging on the high current connections. I know pretty much nothing when it comes to electrical systems to this will be a good learning experience for me. It hasn’t caused me any issues (fortunately, knock on wood) but I just wanted to get some input. Thanks Charlie.


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That voltage reading is from my ScanGauge tool. So I’m not sure if it’s reading the battery or the alt. The battery is still relatively new (7/21) and the alt is a Denso reman unit installed 8/21. So those two items should check out. I just never understood what caused that to happen. Or is it normal?

I’ll do some digging on the high current connections. I know pretty much nothing when it comes to electrical systems to this will be a good learning experience for me. It hasn’t caused me any issues (fortunately, knock on wood) but I just wanted to get some input. Thanks Charlie.


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Our factory Alts are not capable of producing more than 40-42a if you are idling at 600rpm in gear with your foot on the brake. With a fully charged battery the ECU draws 15-17a. Add lights radio, fan and AC engaged and that’s well over the Alts capability at that low idle.

With just my headlight and fogs I’m pulling 38a to 40a. Then add the fan and ac clutch……


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100 Amp alternator option

When I purchased my 2001 Tundra I gave the dealer the options I wanted, there was an option called “Security Guard” I think. It included a 100 amp alternator and heavy duty heater blower
Hope that helps
 
Our factory Alts are not capable of producing more than 40-42a if you are idling at 600rpm in gear with your foot on the brake. With a fully charged battery the ECU draws 15-17a. Add lights radio, fan and AC engaged and that’s well over the Alts capability at that low idle.

With just my headlight and fogs I’m pulling 38a to 40a. Then add the fan and ac clutch……


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So that would lead me to believe that it is normal for that to happen then. I sometimes have my radio on, sometimes I don’t. I wonder why Toyota designed it this way if that would happen?


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So that would lead me to believe that it is normal for that to happen then. I sometimes have my radio on, sometimes I don’t. I wonder why Toyota designed it this way if that would happen?


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A lot of Alts don’t produce more than half their rating at that low of an idle.

I have an amp gauge mounted in my dash to watch it’s output.

It’s not normal to drag down an Alt at idle with “just a radio” unless it the kind you can hear two blocks away.

My 1996 Saturn automatic with a CS120 105a Alt behaved the same way at idle if I had my lights on and fan on max speed. My Manual 2002 idles at 750 and doesn’t have a problem.


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So that would lead me to believe that it is normal for that to happen then. I sometimes have my radio on, sometimes I don’t. I wonder why Toyota designed it this way if that would happen?
Because the battery still charges the rest of the time you are driving, and it isn't discharging while you are sitting there with those voltages. Why overspec the alternator? That's just more cost from Toyota's perspective.

I have a similar alternator (80A Denso) on my 3s-gte Camry (sadly, not enough the same that the 95/105 options from the Suzuki could swap). I can get it to drop down under 11V with everything on at idle (headlights, brake lights, turn signal, high-current rad fans, etc.). Still charges the battery just fine once above about 900-1000 rpm. My 4Runner isn't quite as bad since it has the clutch fan instead of electric fans.

-Charlie
 
Because the battery still charges the rest of the time you are driving, and it isn't discharging while you are sitting there with those voltages. Why overspec the alternator? That's just more cost from Toyota's perspective.

I have a similar alternator (80A Denso) on my 3s-gte Camry (sadly, not enough the same that the 95/105 options from the Suzuki could swap). I can get it to drop down under 11V with everything on at idle (headlights, brake lights, turn signal, high-current rad fans, etc.). Still charges the battery just fine once above about 900-1000 rpm. My 4Runner isn't quite as bad since it has the clutch fan instead of electric fans.

-Charlie


Couldn’t have said it better myself. I did put a smaller pulley on my 70a Alt and now it pushes a solid 45a at 600rpm. I also put LED brake lights in to ease up on the load when I’m on the brake at 600rpm.


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Couldn’t have said it better myself. I did put a smaller pulley on my 70a Alt and now it pushes a solid 45a at 600rpm. I also put LED brake lights in to ease up on the load when I’m on the brake at 600rpm.


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I really like the smaller pulley idea. As your overcoming the idle charging issues in our 3rd gens.. :) Thus creating more amperage. The next obstacle is the temperature issue.

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My Alt at 750rpm will push 55-56a. Tested yesterday on my way home from work. It’s the 70a with the smaller pulley.


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Hey guys,

A few thoughts. first, my status. As best I can tell, my problems originated from the pos cs144 alternators. They weren't charging well and my battery was damaged. putting a solid alternator in just exaggerated the battery's death.

I redid my positive wire from alternator to battery. I also redid all grounds. i'm starting to find having a plusnut tool is the bomb!! Now that there's a new battery, I'm not having any problems. Battery stays charged. There's no corrosion on any contacts after a few months and there's no battery gassing.

On to a few other topics discussed. My understanding of amps is that, provided there aren't any issues with the alternator, amps decrease substantially as the battery gets to the fully charged state. So regardless of the alternator's potential or max output, it's not putting that out at all times. I only see this happening on the rare occasion I need to winch. I don't really wheel. But I do travel solo from time to time. Got stuck ONCE. Never again.

As for the wiring to the fuse box, again, my understanding is that you wire/fuse for the draw. I'm not drawing anything of any additional import. I have a stereo and amp and that's about it. They've been in the truck for 24 years. No issue. No aftermkt light bars or accessories that would be considered a big draw. I like keeping my 4r looking close to stock but for a small lift. So there's no reason I should need to boost the wiring to a fuse box that isn't any more tasked than a completely stock vehicle.

Look at it this way, couldn't you add a 12awg to the battery to power something small? Of course, as long as the 12awg is suitable for the DRAW, it's not a problem. I believe the same applies here. I maintained the same gauge when I extended the fuse box wiring. I have no concerns here. The battery is only going to put out what is drawn from it. all large gauge wiring is oversized, uses FTZ lugs/crimper, are double crimped and incorporates adhesive lined shrink wrap.

Appreciate everyone chiming in. Hope everyone has a safe and happy holiday. I'm on to my next set of projects:

1. new tires. sticking w 265/75/16 but going back to load range C as I won't be towing a trailer much longer and I really think this was the main contributing factor to my mileage dropping around town a bit. still got 21mpg on my recent trip to ouray, co.

not sure if this (tires) is why my steering is sticky going around corners from time to time (it's not persistent). tread is starting to get a little low. it has a new steering rack, new ps pump and reservoir (all oem) and the fluid is relatively new. So not sure what else it could be. it's a relatively recent thing. any thoughts appreciated.

2. axle swap (new seals) and rear 4:30 elocker (overhauled by zuk)
3. brand new front elocker and a re-gear to 4:30 (fr 4:10) (zuk's the man!)
4. new front differential bushings
5. new oil cooler seal
6. drop oil pan and redo the seal
7. new door actuators all the way around. had an interesting thought here. I think I'm going to put a switch inline to the rear door actuator so I can disable it. this would likely stump any thief trying to get into the rear cargo system I'm planning to build. If you can't unlock the door via the powered lock/unlock button and you don't have a key, you're probably going to move on to an easier target. If you can't open the door, you won't be able to access the cargo draw's content without a heck of a fight.

8. attach a kickass shower tent. got their little lithium powered shower head too. looks like a great compact system. i may double it's use as a sink faucet.
9. install and plumb a ironman 4x4 13gal water tank against the back seat. it will sit betw the back seat and the cargo system I'm building. the cargo system is going to straddle the wheel wells. the single draw will hang below that. I don't see a need to have a box inside a box. one draw w/ oversized slides. i'll route out the inside walls a bit to incorporate draw dividers in a number of configurations. the front of the draw will double as a table w/ two piano hinges thus allowing it to unfold twice the height of the draw. should create plenty of table top space and i'll be able to adjust it easily so it's always a level cooking surface. i'll be able to pull the draw out while still using it as a table to get at whatever. i can't think of a lighter, simple design. i've read A LOT.


10. fix or replace the windshield fluid tank
11. install the rad rubber liners I've been sitting on for a year
12. extend the manual transmission breather up into the dash
13. extend the breathers in the engine bay (already did the rear diff breather long ago)
14. rewire the radar
15. spare belts and a LBJ

....and head down to baja for a few weeks to celebrate it's completion.

I LOVE this truck. Bought new. Still no rust. Love'em and they'll love you back for a long, long time.

Really appreciate this community.
 
Electricity travels on the outside of wires on the surface through the electrons of atoms. Ts how the energy flows.

You understanding it though. On circuits you are correct on fuses. You always create the circuit to just be slightly less the the fuse so the circuit burns the fuse.

Here were gets interesting. The LED are diodes. So they only let current flow on direction.

This is way the high beam indicator etc will not work.

What's concerning me is that in certain situations. These led in circuits wil not let the fuse burn properly .

This is why on occasion we are seeing dash burn up because the circuits are designed for this.

The only workaround are leds that are resistive loaded or resisters in the circuits to have the circuit function as it should.

Anyways, what you can do is always jump a wire gauge up one or 2 sizes then the current load of your circuit then just put the proper fuse in. This way it will burn the fuse before starting to heat up and melt your wiring. Plus only a few amps above your maximum current capacity.

This is why Voltage on fuses isn't as important. The fuses just burn open to protect other things. As that's their purpose in the circuits


I hope this helps in your understanding of your project. :)



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Electricity travels on the outside of wires on the surface through the electrons of atoms. Ts how the energy flows.
This is only true at high frequencies (think radio, etc.). Multi-stranded wire for DC applications is for flexibility and vibration resistance, not extra surface area. Static applications - AKA home wiring - is solid conductor because it is cheaper and doesn't move once installed.

-Charlie
 
This is only true at high frequencies (think radio, etc.). Multi-stranded wire for DC applications is for flexibility and vibration resistance, not extra surface area. Static applications - AKA home wiring - is solid conductor because it is cheaper and doesn't move once installed.

-Charlie

I am not sure about that one. Granted your are right on the DC multi stranded being for flexibility and vibration.
I theorize that it travels on the surface area of wires wither they are stranded or or solid would be application and I am not the only one on this theory as it has to push the valance electrons down the wire.

Current isn't concerned about wither its AC or DC. Its the flow of the electrons that matter. This is why with higher amperage loads, you need thicker larger diameter wires.

If the surface area or size exceeds the wire fuse amperage level what happens? It melts and opens up the circuit. Fuses are just melt-able links that are supposed to melt when the amperage exceeds the specified rating.

Granted temperature and resistance need to also be considered.

Could that particular theory be wrong.. possible but mostly when wires melt down the first that goes is the insulation then the wire itself which is due to heat resistance of materials used.

Plus they also seem to you really look closely burned from the outside in thus is to why I think this theory is correct. :-)

And Yes I know this Theory goes against the grain and everything says otherwise. As the standard has more surface area then the solid and this is why its a Theory. As solid wire is can't take heat then stranded can either.

So its possible its a bad theory and that does need to be mentioned on here so thanks Charlie.. :-)
 
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Plus they also seem to you really look closely burned from the outside in thus is to why I think this theory is correct. :-)
Burning, aka oxidation, happens in the presence of oxygen - it HAS to happen from the outside. Otherwise, it is just melted metal that reforms exactly the same once cooled off.

Beginning info:
Skin effect - Wikipedia

There's a lot to it. AC vs. DC has a definite difference in effect in conductors. (I'm an electrical engineer...)

-Charlie
 

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