Phantom Electrical Issues

[kayakred]

New here, but hope to spend some quality time.

So...

My wife has a '11 4Runner all stock. Its never give us any trouble until today. She goes to leave work and it won't start. Acts like the battery is dead. Fortunately we have a Jumpstarter that happened to be in there from our last road trip. Hooks it up, and it starts right up, no worries.

Here's where is gets weird...

If she's traveling at a constant speed and hits the brake the instruments, radio and everything lose power. Very strange. Like there's some kind of short.

Anyone have any thoughts before I have to take it to the dealership?

 

[ziefh]

If you turn on headlights and try to put as much load on the battery as you can does it still happen(while not moving)?

 

[eddiebx]

Have you checked your battery terminals for corrosion and also to see if they are securely fastened?

 

[Antman]

Have you checked your battery terminals for corrosion and also to see if they are securely fastened?

^^^^My money is on a loose battery cable too.

 

[Hellamatic]

I had the same problem with my Tundra. Checked the battery cables and they were good. I ended up fixing it by pulling apart the connector on the alternator, shooting it with contact cleaner followed by WD-40, and reassembled.

 

[DannyLlama]

Alternator?

 

[2013Trail]

Of course a loose cable can wreak havoc on the electrical system. But, a weak and/or dying battery can cause some unusual symptoms. It can also cause the alternator to "overcharge" the battery, eventually causing the alternator itself to fail. I suggest you take your battery out and take it down to Autozone or O'Reilly and have it tested.

 

[kayakred]

Thanks for the input!

I wasn't able to recreate the issue while not moving. In fact I wasn't able to recreate it at all at first, and had assumed it was something my wife did.

However, after driving at ~70mph for about 15 min I exited the interstate and hit the brakes to slow down for a light. It was then I saw what she was talking about. Headlights turn off, and every warning light in the dash comes on for about 1.5 secs. Then everything comes back on and back to normal.

Checked the cables, they look good. I guess the next step is to pull the battery and have it tested? I'm hoping the alternator isn't involved but we'll have to see.

Any thoughts?

 

[eddiebx]

Have you noticed if you must drive to ~70mph and for a few minutes or longer to reproduce this? What if you just started it and got up to speed quickly and hit the brakes?

When you say every warning light comes on, do you mean literally every single one, as if you just turned the key to the on position and they all light up momentarily? Or is it just the check engine light, slip light, ABS, TCS, VCS, etc..?

Has your 4runner ever been in any kind of collision or had any major work done where they might have needed to disconnect and reconnect some wiring harnesses?

At this point the only thing I can think of is, if it was actually a warning light, perhaps you can try to see if there is any stored error code in the computer...if there was that might be some clue to help you track this down...

 

[Stifler]

warranty?

 

[Hellamatic]

Its definitely an issue with the battery or cables, or the alternator/alternator connection - nothing worse than that, so don't worry yourself too much and drown in a glass of water.

When the computers in the truck see a drop below a certain voltage threshold, they fault and reset themselves. You can typically recreate the issue by activating an accessory with a high load while driving - I found either rolling down all the windows at once, or having the trac control kick on will do it.

You'll likely find that if you shut the truck off when it is faulted, it will appear that your battery is completely dead. After the computers do their full reset cycle (approx a minute or so,) you'll find that power is restored.

Load test the battery, check battery connections, check alternator connections. Then drink a beer, because chances are that you've fixed it after going through those steps.:guitar3: