2013 Tundra no battery light. charging system faulty

HELP!!!

No battery light when ignition is turn-on. Normally it’s comes on, then goes off when engine starts. It this case , none. Good alternator, good battery and cable clean , fuse under dash LH-IG good , still not charging . Diagnos C1241 reads low and high voltage also pointing at skid control faulty. Dash battery symbol not lite when key is turn-on position before start up engine.

 

Is it a Denso alt or some reman?

And please define "good alternator"...

 

I would pull the battery and have it tested out of the vehicle, it may be more work than required, but Toyota batteries are not that good, IMO.... If its good then reinstall it and make sure the ground is on tight, like Zeus himself has to come down and remove the negative terminal. I've noticed that when its slightly loose your electrical system will be all over the place. Inspect your wiring harness, from the battery to the alternator and your ground cable. Ensure that nut is tight and the harness is fully seated. If the wiring is slightly damaged or corroded your problem may be the wiring vice equipment.

 

Toyota Tundra 4.6 L Crewcab 2X . I came to found out thet the Battery light at the dash is not coming on when the key is turned. The battery light supposedly lite up when key is turned-on at the ignition and goes off when engine starts. No battery light through whole start up. I have checked the harness terminal at the alternator , (with no key on) 1 (S) blk/yellow slut hole light up with DC electric test light. and rest 2 (IG) grn/yellow, 3 (M) Red and 4 (L) Blk don't light up. Vice versa when the key is in on position (same). I light tested the (charging system) fuses seats they light up when key is on. I battery symbol yellow is only a permanent symbol i found out but the battery symbol below it doesn't come on red when key is turned on. My understanding is that maybe the engine light bulb (behind the gauges panel, cluster) is burnt out where it does not continue the electric circuit to circulate. Who knows!! The vehicle engine can run but lack charging the battery, thats the problem.

 

Alternator bad. Me hungry.

 

Alternator been change over two x with brand new one.

 

Maybe mice got hungry..

 

I'm to lazy to pull up our truck but this Yoda has 4 fuses for the alternator/charging system. Six if you count the two into gauge cluster (combination meter). Lexus IS-350 shown below. No access to live schematic atm.

Start w those fuses. Those to the meter are suspect as they light the warning light and are very low amperage.

Edit: See POST #25 FOR A 2010 4.6 CHARGING SYSTEM!

 

Have you checked grounding points? What are the chances that one has become loose or has corroded over time. Especially that one grounding point near the battery? Mine was loose at one point and time, so I've had a habit of checking it when I check fluids.

 

Your alternator has a fuse under the hood also. I believe it’s in the fuse box next to the battery, should be labeled Alt-S. Prolly want to check this.

 

The battery light supposedly lite up when key is turned-on at the ignition and goes off when engine starts, but No battery light through whole start up.

 

Maybe but I light test the fuse inlet both ends (w fuse pull out) on each charging system fuses . There is 4 I tested ( 3 in hood and 1 under dash). All lite up.

 

so, it's not reading the battery technically?. I would start by checking the fuses/relays from the sheet that @KeepOnTruckin posted, and check wiring from there.

 

Maybe focus on the harness between the alternator and battery, if fuses are good, double check grounding cable and grounding points from the battery to the chasis

 

So there is 2 fuses behind the cluster gauge ( combination Meyers) ?

 

The grd points at battery box fasten to fender , 3 separate grd wires ( 1 from battery and 2?from under main fuse box) looks good and fasten tight.

 

There is 3 fuses I checked in main fuse box under the hood and fuse looks good also replace large fuse plate (alt 180A & 140A) as well w new one. Alt-s 5A & met fuse 7.5A & alt 5A , scrap it clean at fuse side and inlet seat, Then light tested , it lite on one end of inlet seat, I’m assume wire is good. I went under dash (driver side) did the same w LH-IG 7.5A fuse , light test the inlet seat, it lite up but the other seat didn’t , I’m assume the electric current can still go thru if fuse back in. That’s my findings . I been told on this chat that there are 2 more fuses behind cluster panel ( combination meter) , yet I have gone far to check. It will take the world to take the dash board apart . Hope someone have a video how to take it apart . Again, The vehicle engine can run but lack charging the battery, thats the problem and no battery light when ignition is turned on . The abs yellow light is on too. I may post a photo here in a bit on ignition on ( photo on cluster panel ).

 

Alternator is changed 2x w brand new one. Still the same problem , no charge at battery. I even had the auto zone test it at the exchange . It’s good alternator. I didn’t check for manf. on brand new exchange ,,, it’s from auto zone.

 

In photo, as you can see the battery light does not come on red, when the ignition is turn-on ( the white battery light above volt gauge is identification symbol. I notice ABS is on yellow light too , it suppose to come on for split second and goes off but stays on when ignition is on for over 5 second , it stays lite yellow. The skip symbol yellow light is also on. The maint. Requir. Stays on yellow when engine is running .

 

Are you sure your diagram is w 2013 range? I have 2013 charging diagram where L (blk wire) goes directly to combination meter not to engine control module (ecu). Only (m) red wire goes to ecu.

 

Battery light at gauge cluster is not working even when engine starts. It normally light up when ignition is turned to on. None. No red light coming on the battery icon (symbol).

 

Maybe the voltage regulator has gone bad? just short of wiring will be your next step, unless the bulb has died.

 

The voltage regulator in embedded in the brand new alternator. Will bulb blow out at battery light would cause it ?

 

I highly doubt its a light bulb, but its a probability. Odds are its wiring.

 

OP here is what I have for my 2010 4.6 4x4. I can't imagine it's different for yours. The combination meter light appears to be LED according to this.

A test you can do to verify the dash light is take 12v incandescent test lamp and unplug the connector, and take that pin to ground with the ignition on. The indicator should light. And if you poke something hot, no harm as it lights your test lamp.

 

A few things, its not a bulb in the instrument cluster is an led and very unlikely to fail. The 2 fuses you mention for the instrument cluster control the entire thing. One of the them being blown would not cause a single indicator light to no longer work.

You need to go back to focusing on the 4 pin connector at the alternator, more specifically the Green/Yellow IG wire on pin #2. If it is not going to 12V high with the key on (as you mentioned above) this is your problem. This IG signal of 12V is what wakes the internal regulator wake up to start working when the truck is started. If the regulator never wakes up the alternator will not charge and the light on the dash will not work.

Start the truck (or at least make sure the key is ON, not ACC) and check for voltage on the Green/Yellow IG wire on pin #2, you have to have 12V here. If you don't make very very sure the 7.5A LH-IG fuse is good (interior fuse box under dash). If the fuse is good then check for continuity from the fuse socket to the Green/Yellow IG wire on pin #2. One side of the fuse socket should show a direct connection (continuity) to the Green/Yellow IG wire on pin #2. If not you have a break somewhere in between and this is the problem.

If you don't have voltage to the Green/Yellow IG wire on pin #2 with the key on, you could quickly add a jumper from the positive battery post to the Green/Yellow IG wire on pin #2 to give it 12V. Doing so should make the truck start charging. This would be a quick temporary test.

 

FYI if the turn signals/bkinkers work with the truck on or running the 7.5A LH-IG is good. It powers the flasher relay also which runs the blinkers.

 

The wiring could be bad, but hard to trace where people sending me different charging system diagram. Need a pro here,, perhaps a person who know how to test wirings.

 

If you know how to use a voltmeter/multimeter I just told you how to test the wiring. The continuity setting checks for breaks in the wire between the two points.

Read my post above again I laid it out pretty well. You have to have ignition 12v with the key on to the green and yellow wire or the alternator will never charge no matter how many times you replace it with a new one. If you take it to any reputable shop they will pretty much do what I load out above. This is the proper way to test it.

The wiring diagram in post 24 right above mine is the correct one.

The diagram I posted is just a cropped version of it showing the ignition wire only. The part you need to focus on.

If you read here (https://www.tundras.com/threads/low-voltage-ive-replaced-everything.106100/#post-2730092) you will see this guy had almost the exact same issue as you and I told him how to fix it. His was the fuse, if your fuse is good you probably have a break in the wiring.

 

YOU can find wiring diagrams here..

Ultimate TUNDRA Wiring Diagrams Collection | Toyota Tundra Forum (tundras.com)