Speculate on what happened to my truck

I own a 2010 Toyota Tundra TRD with 80k miles on it that has been a dependable workhorse for me. The only money I put into it has been routine maintenance items like brakes. Back in February, I replaced the battery as it was the original one and I didn’t want to get stuck during the winter with a dead battery.

Yesterday was a normal day. I left the house in the morning to run some errands that included a trip to a town about an hour away. I finished up there and was returning home. Everything was as it should be. It was late in the afternoon so I stopped to pick up the mail at the community mailbox. Because my mailbox key is on my truck key ring I had to turn off the truck to pull out the key so I could get the mail.

I returned to the truck 30 seconds later, jumped in, put the key in and turned it. Nothing happened. The truck was completely dead as if one the battery terminals had become disconnected. l tried starting it multiple time, but it was dead.

None of the electronics on the tuck worked. Not the radio, no lights on the dash, nothing. A friend of mine happened to drive by and asked if I needed a jump. I said I did and pulled out my heavy duty jumper cables. I popped open the hood and checked the battery terminals to see if one was loose or had fallen off. Both of the terminals were tightly connected and there was no corrosion to speak of.

I then hooked the jumper cables to my battery and as soon as I did I could hear the beeping sound of the truck telling me the driver’s door was open. Without hooking the jumper cables to my friends truck I jumped into my truck and it started up like nothing was wrong. It went from completely dead to perfectly normal just by putting the jumper cables on my battery terminals.

This makes no sense to me. Any speculation on what happened? It has worked flawlessly ever since that incident yesterday.

The cables or terminals or posts are corroded in such a way that is invisible.
Remove the terminals, clean them up, and the posts, and re-install. Check that the wires going to the terminals are not corroded.

100% agreement with beowulff.

Same thing with my used Prius. Every couple of days the car was just dead and two minutes later would boot up- randomly. It escalated from a once a month to every other day over a couple of months. Battery tested fine. A little scrubbing of the terminals and tightening of the bolts and not a problem since.

Modern cars are very sensitive to low battery voltage. Some will act progressively by disabling energy-hungry items like heated screen and stop-start. They go on to disable everything including the heater-blower and radio.

It’s possible that yours does not have this progressive function so it sees low voltage and refuses to work.

I concur with beowulff.

The symptoms you report are best (indeed, only) explained by the battery becoming electrically disconnected. This is reinforced by seeing the problem fixed simply by clamping jumper cables onto the terminals.

Not trying to derail, but on a tangent:

I have a 2012 Subaru that I bought new (60K miles). Like dolphinboy, the only money I have put into it is new rear brakes (well, and tires). This winter I thought “I should replace the battery before I get stranded”. Then, I was gifted one of those jump starter thingies (the lithium battery pack) so I put off the new battery. It’s now 7 years old. It looks like dolphinboy made it 9 years without it failing. How long do OEM car batteries typically last?

In the old days of always buying jalopies (or being given them), I dealt with dead batteries…a lot. I would buy the cheapest one you could get and hope for 3-4 years out of it. Are OEM batteries just a higher quality battery?

So how does clamping on the jumper cables change anything? Are you say that by doing that I disrupted the invisible corrosion enough to bring everything back to life? BTW, the terminal clamps are already tight, and there is no way to tighten them any more.

Just a WAG: It was a coincidence and there is an issue with the ignition switch/lock cylinder or the electronic chip in the key. If it happens again, try a spare key if you have one or wigging the key around a bit.

Actually there is, in a way. The jumper cable clamps – especially robust clamps like on the OP’s heavy duty jumper cables – can apply enough squeeze to the battery cable end to deform it a bit. In this case it may have been enough to displace some corrosion and regain electrical contact with the battery post.

ETA: Remove the battery cables from the battery and clean the battery posts and cable ends (inside and out) till the contact surfaces are shiny metal, ASAP to avoid a recurrence.

Speculate, eh? Alien spacecraft were nearby. Possibly with bright lights that might have given you sunburn. Possibly looking, to some, like an ice cream cone. Have you found yourself obsessed with visualizations of mountains? Or one specific mountain since?

Ditto on what** beowulff **said.
I’d add that using dielectric or white lithium grease will create a barrier to keep moisture and corrosion on your terminals.

How old is the battery? In my experiences, batteries of a certain age tend to be fine until they all of a sudden aren’t, with little warning.

-Edited to add: I didn’t see the part where you said it was replaced in Feb, so belay that theory!

Corrosion inside the cables also happens. It’s possible the cabling may be loose at the clamp, or you have a loose ground and the movement of the cables when you piut the jumper cables on re-established the contact. That’s less likely if you haven’t had problems otherwise though. As above, clean the terminals and clamps and apply a barrier film of some kind. Dielectric or lithium grease work but attract dirt. There is also battery terminal sprays that apply tacky but dry out. I use that normally.

Agree that corrosion is the most likely answer. Since the battery is new it’s most likely on the inside of the cable clamps.

Other possibilities:

One of the battery terminals is loose or poorly manufactured on the inside, and jiggling it put it back into position.

There is a sensor on either the clutch (if you’ve got one) or the brake, that tests whether you have it deployed before allowing the truck to be started. That sensor could be going bad, or when jumping back in so quickly you didn’t depress it far enough.

The battery you bought is just a bit lower in voltage than the original and the fuse/circuit leading to the computer is about to go.

We had an old farm truck that wouldn’t engage at all if the steering wheel was in the locked position. Most vehicles the key won’t turn in this case, but with that truck it would turn, it just wouldn’t do anything else.

There’s a loose connection somewhere important, like the alternator or the computer, which prevented the circuit from completing. Did you hit a big bump or something right before this stop?

The grounding wasn’t attached properly when the battery was replaced.

Good point. I had a similar problem which traced back to the ground cable to from the alternator having a short.

I have a 2007 Chrysler 300C that has the original Daimler-Chrysler battery. This is far longer than any other battery has lasted, in any other vehicle I’ve ever had. Still no signs of slowing down. I do wonder if some current practices of battery location help with longevity. The Chrysler battery is in the trunk. My wife’s car has it under the passenger seat. Perhaps moving the battery from the heat and exposure of the engine compartment is beneficial, if inconvenient to access.

It may have helped get through the invisible corrosion. Once you went to check if the terminals are tight you may have moved it enough, but the battery was already dead. As soon as the other battery was connected from the jump start car, not only was power flowing into the car’s system, but through the corrosion into the dead battery, charging it up, perhaps creating heat, or just playing with the terminal broke the corrosion enough.

If this was the case your battery was not being charged, perhaps from the voltage drop to the battery because of this corrosion, resistance. You could clear it by wiggling the terminals, but the battery was already dead at this time and you wouldn’t see any effect of that.

Don’t get too focused on the battery connection end of the system. As others have said, be sure of the other end of the ground, and the other end of the hot cable to the starter. Remove and clean those connections too. Once you are sure of the cleanliness and connection at both ends, then you possibly have had one of the cables go bad inside where you can’t see it. They do that.

The jump start added extra aux power that overcame your connection issue. So your system may work fine for awhile and not have the problem, and you think you have it fixed, then it comes back at an inopportune time. Be sure of your connection integrity on BOTH ends and then consider the cables themselves.

AIUI he never jump started the truck. He just hooked up the jumper cables on his end, and then heard the beeping. This seems to indicate a loose connection somewhere that got jiggled or bumped in the process of opening the hood or attaching the cables.

Dallas Jones is making all kinds of sense.

The OEM battery (a Panasonic) in my 2004 Toyota 4Runner lasted just over 13 years for me. The vehicle had about 230,000 miles at that time.