Total electrical failure at hwy speed

Hi there,

My daily driver project truck (2UZ-FE double cab 4x4) had a totally new issue the other day. I went to start it in the driveway, and it had no power (no lights, gauges, beeps). That's not abnormal as lights get left on or doors ajar occasionally, so I quickly jumped it and was off. That changed when I was 10 minutes out of the driveway and up to highway speed on the interstate when the truck instantaneously died. It lost all electrical power, gauges froze where they were, engine died, power steering and brakes of course went as well.

I was able to jumpstart it again and got it home. Since then, I've been unable to replicate the problem and it has been fine for about an hour of idling and driving.

So, does anyone have ideas as to the cause of this? I did find that one of my battery terminals was loose and I tightened it. Ground connections are all good. Wiring to battery, fuses, and alternator is all clean and connected. Engine runs completely normally. I tested battery with a multimeter and got 14.5v with engine on, and normal charge with engine off.

Was this a fuse/relay problem, battery connection, faulty alternator, or something else entirely? Thanks for the help!

 

Aliens,Man space aliens......

 

Happened to me too but parked. When I needed to pick a friend from the train station, turned key, nothing. No clue what caused it. And it cleared up after two minutes. Hasn’t happened again in 3-4 years.

Best guess? Freak event. Likely a short. Carefully inspect batt terminals with a push/pull and inspect for separation,, and cables for corrosion inside the wires. I don’t remember if more tips are in here or not. https://www.tundras.com/threads/so-you-wanna-buy-just-bought-a-1st-gen-tundra-eh.115928/

 

Reading the first half of your post, this was my first supposition. That, or a bad cell in the battery. But since you confirmed a loose connection, that would absolutely cause the issues that you listed. I would check the battery voltage over an hour or so - when you turn the vehicle off, 5 minutes after that, 30 minutes after that, and an hour after that. See if the battery voltage is dropping more than a quarter volt over that time period. If you have a bad cell, it will usually drop ~2 volts over that period. You can also have the battery load tested at an auto parts store and/or measure voltage while cranking (obviously, you need to have a helper to start the truck while you watch the multimeter, or long enough leads to prop the multimeter where you can see its through the windshield. If your battery drops below 10v while cranking, you have a weak/bad battery.

But, again, a loose connection will behave just as you described and go from 'works just fine' to 'no juice, anywhere'.

 

I totally missed that line. I was just waking up while reading. Yup, broken or loose terminal will 100% cause it.

 

Thanks for the help everyone! Makes sense enough to me.

 

Is your battery tied down proper? I wonder if it maybe touched the hood?