[fezzik80]

2006 Tundra DC 4wd with 240k miles on her

This is my wife's truck - her pride and joy to drive - so, since I don't drive it every day, I may be missing some information.
The truck will start and drive in a normal fashion and these symptoms came on one day, seemingly without warning.

The symptoms:
*Battery will hold a charge but the alternator is not charging the battery - when the engine is revved above 2000 rpm the battery needle waivers but it stays down below the middle mark.
*Dash lights lit - ABS 4HI 4LO
*Brake lights and blinkers are inop - but the headlights and hi-beams work as well as the hazard lights
*Seat heaters inop
*Electric seat adjustments inop
*Bed light inop
*Radio inop
*Wipers inop
*Windows inop

I've checked each of the fuses with a multi-meter.
One 7.5 amp fuse was blown in the engine bay labeled RSE (rear seat entertainment) - replaced.
The battery has been removed from the truck, cleaned and charged - the terminals have been cleaned as well.

Is the alternator bad and all these other symptoms are pointing to that?
OR, is the alternator part of the symptoms as a whole that point to a different problem?
Input is greatly appreciated, if it's not constructive at least let it be entertaining.
I'll be here rubbing my chin and scratching my head.

 

[fezzik80]

Update:
Before calling it a night, I disconnected the negative terminal on the battery.
This morning, connected the terminal, started the truck, everything works. I turned it off (I think you can see where this is going) and remembered I didn't check the alternator. Started the engine again and all the gremlins are back. Still scratching my head.

 

[Tundradrenalin]

If those warning lights on the dash are lit and on, you should be able to put a scanner to the OBDII and get some codes. Your alternator could be shot.

 

[xsnrg06Limited]

This removed my semi-Limp Mode, TRAC OFF, VSC OFF, Slippery Light, CEL Dash Lights and have driven about 75 miles with no return, knock on wood.
I still know my 2006 needs me to install the new O2 sensors, change that pass side valve cover gasket seals/spark plug check/Ign Coils, (use REAL Denso/Toyota ONLY if expecting them to work/last),
clean MAP...
Waiting on new Autel 6510 to chase my demons...

Here is the step by step.

Disconnect the Negative terminal the dico the Positive.
Get a jumper across both disconnected terminals, NOT BATTERY POSTS.
(Clean Battery Posts; I know you did. Check wires/ground)

Let it drain at least a few hours.

Reconnect Positive fully.
Reconnect Negative fully.

Your ECUs should be reset.



If this doesn't work at least it was free!

Sounds like bad/fading Alternator or a squirrel at some wires!

Good luck

 

[fezzik80]

If those warning lights on the dash are lit and on, you should be able to put a scanner to the OBDII and get some codes. Your alternator could be shot.

I did try to put my BlueDriver on the OBDII with the truck idling and it didn't power up. Forgot to mention that.

 

[fezzik80]

This removed my semi-Limp Mode, TRAC OFF, VSC OFF, Slippery Light, CEL Dash Lights and have driven about 75 miles with no return, knock on wood.
I still know my 2006 needs me to install the new O2 sensors, change that pass side valve cover gasket seals/spark plug check/Ign Coils, (use REAL Denso/Toyota ONLY if expecting them to work/last),
clean MAP...
Waiting on new Autel 6510 to chase my demons...

Here is the step by step.

Disconnect the Negative terminal the dico the Positive.
Get a jumper across both disconnected terminals, NOT BATTERY POSTS.
(Clean Battery Posts; I know you did. Check wires/ground)

Let it drain at least a few hours.

Reconnect Positive fully.
Reconnect Negative fully.

Your ECUs should be reset.



If this doesn't work at least it was free!

Sounds like bad/fading Alternator or a squirrel at some wires!

Good luck

I may give this a shot this evening, let it drain like you said while I chase down wires and ground connections.

 

[jgrauman]

Check the voltage on the alternator, sounds like it's shot

 

[fezzik80]

Found the culprit.
I overlooked a module when I was checking the fuses.

30 amp "Towing Tail" according to the diagram.

Replace the fuse and everything (including the alternator) is back in business.
I'm still scratching my head but for a different reason now - why does so much rely on that fuse working?

Thanks to everyone who contributed.

 

[Jonesy]

Thanks for the follow up. We can all learn a little something here . . .

 

[xsnrg06Limited]

Fantastic to hear.
Good lesson.

 

[James777]

Found the culprit.
I overlooked a module when I was checking the fuses.
View attachment 153335

30 amp "Towing Tail" according to the diagram.
View attachment 153336

Replace the fuse and everything (including the alternator) is back in business.
I'm still scratching my head but for a different reason now - why does so much rely on that fuse working?

Thanks to everyone who contributed.

Glad you got it Resolved 👍

 

[orly67]

Found the culprit.
I overlooked a module when I was checking the fuses.
View attachment 153335

30 amp "Towing Tail" according to the diagram.
View attachment 153336

Replace the fuse and everything (including the alternator) is back in business.
I'm still scratching my head but for a different reason now - why does so much rely on that fuse working?

Thanks to everyone who contributed.

Inconceivable!! Lol

 

[fezzik80]

Ok. Maybe that was too easy. It's been a couple of days and my wife called to say the same symptoms are back. Yea!!!

After work I started testing fuses for continuity again - nothing blown under the steering wheel, nothing blown under the hood. Or so I thought. All the fuses from before were intact... this lead me to check the main fuse or the fuse block as it's sometimes called. That's when I ran into the PO's "ingenuity". See pics.

I didn't know how to gain access to the fuse but thanks to a short blurb in this thread Gen 1 Sequoia build - Slow but Determined
I was able to get it done. New fuse online is about $20, I'll call the stealership tomorrow and see if they have it in stock at a comparable price.

 

[xsnrg06Limited]

Those dang POs!

 

[hewitt-tech]

Ok. Maybe that was too easy. It's been a couple of days and my wife called to say the same symptoms are back. Yea!!!

After work I started testing fuses for continuity again - nothing blown under the steering wheel, nothing blown under the hood. Or so I thought. All the fuses from before were intact... this lead me to check the main fuse or the fuse block as it's sometimes called. That's when I ran into the PO's "ingenuity". See pics.
View attachment 153350 View attachment 153352 View attachment 153353
I didn't know how to gain access to the fuse but thanks to a short blurb in this thread Gen 1 Sequoia build - Slow but Determined
I was able to get it done. New fuse online is about $20, I'll call the stealership tomorrow and see if they have it in stock at a comparable price.

That will do it! It feels good when you finally have the smoking gun to point to as the culprit.