Electronic / Battery Apparent Issues

Having some weird electronic issues.

• Wipers started running nuclear fast when on
• Battery light on, along with lower charging, and then seems to go away and comes back
• Battery light is NOT on but showing lower charging
• Intermixed is lingering code P0500 (speed senor) that comes and goes, but not sure if related
• When I run a code checker, it is pulling zero codes
• Some dash shots shared at various stages
• My battery is new (last 6 months) and is an AGM

Any thoughts? General thought would be (1) Serpentine belt is ready to be changed ( but not hearing slipping noise) or (2) alternator is going in and out.

Any help / thoughts?

 

Most certainly the alternator. Buy a re-manufactured Denso to match what you have.

 

@w666 thanks. The one thing that I did not add was that this issue is intermittent - after a bit battery light goes out and "normal" charging appears... assuming same answer?

 

Stupid question, but have you also considered the battery may be bad?

That said - I almost burned my truck to the ground due to bad alternator. Was driving to work, low batt light came on. I assumed battery took a dump on me. There was a NAPA 1mi away, so I went there. Swapped out the battery with a new NAPA Gold batt. Fired the truck up, went to leave the parking lot, noticed wisps of smoke from under the hood. Whipped it around, parked, opened the lid, and the gd alternator was on fire.

Follow procedures to test the battery and the alternator. I agree, one is your culprit. Weird things happen when you under-volt stuff. And be aware, swapping in a new battery with a weak or dying alternator can have some pretty dire consequences, as I learned the hard way. The alternator slowly failing degraded my battery to the point when the new batt went in, full volt, full amp, alternator went BZZZZZZT.

 

Thanks @shifty`

 

"Intermittent" does change my answer...but Shifty is right, it's either one or the other.

 

I will get both the Battery and the Alternator tested. Like I said, Battery is fairly new, but never know. Alternator is 16 years old!

I guess the good news is that I literally just bought a backup alternator to have in case it breaks down on the trail. If that is the case, I guess I planned it about right.

 

The comment about 'intermittent' has me leaning more towards the alternator. But really, the only way to tell is to test. Or, if nothing comes up after testing both and you have the parts, time, and know-how, swap in your backup alternator to see if it persists.

 

I’d make sure all my gnd points are good also and not adding to the puzzle.

 

I vote battery.

 

I vote voltage regulator in the alternator.

 

Ok, so I tested the system tonight. Volts on the battery were ~12.6 before start. Volts when no load was 13.5 -13.6. Volts under load was ~13.4. The negative lead voltage drop from the alternator (put positive lead on it) and negative battery terminal was -0.021 volts.

I think my question is that with no load or even normal load, I would expect more than 13.5 - 13.6 volts, right? Something at least 14.0+ with no load? Certainly 13.4 is higher than 12.6, but seems like it should be putting out more.

 

I have an Ultra Gauge in my 06 Tundra and my voltage is in the 13.4-13.8 range with and without load

 

While that voltage falls on low side of what most alternator voltage regulators put out, I personally like to see something above 14.

from 2005 Tundra FSM....