Changed the battery in my 2017 Tacoma. Everything went wrong.

Died old was the, uhm, joke.

 

Funneh

 

These trucks are complex and unforgiving.

You have to diag each system with an eye on the relationship to the other modules.
It’s not fun.

It has to be all together to start and work the systems that are not available.
I’m on the last leg of a lightning strike truck which will be about $10,000 in repairs
Between electronic ecu’s and sensors, displays, and labor it’s been a mentally taxing repair.
Small victories after long diag pin testing hundreds of wires and tracing systems.
Making one system come alive after putting one part in , that your confident it needs, does not mean the system will be 100%. Then you move down the line.

The ecu’s do have some internal protection,I have been told. However every car I see with things like this are not cookie cutter repairing.

I’ve had crossed jumped cars burn wiring, take out ecu’s, fuses.
I’ve seen then take out only the alt fuse
Some the abs ecu only.

You just never know.
But it takes time. I can’t be rushed.
The journey is never certain.
Sometimes the cust gets lucky
Sometimes the cust gets bad news.

He needs to get the diag started.
If things aren’t working you can’t guess.
It is what it is.

 

Its not hard to add reverse polarity protection to some circuits, and automotive circuits are tested for all kind of random stuff ( a fun one is the alternator load dump) But I doubt Toyota would see it as being worth the trouble since this is such an uncommon case.

Is cross jumping with 2 batteries involved going to be different than reverse polarity with a single battery? Seems like you'd have a potential for +24V with 2 batteries.

 

No your shorting the batteries against themselves.

 

That won’t work, anybody can make a triangle fit onto a round post.

 

Reverse polarity wont happen, but I wondered about both batteries putting out 24v with my dual battery setup if my switching regulator does something bad...

 

If anyone wants to know why they historically don’t have reverse polarity protection, this is why.

Reverse polarity protection would require a diode, or an number of diodes, to prevent reverse flow of current. Diodes, by their nature (at least the silicon based ones) have a fixed .7V drop across them, which is insignificant at higher voltages, but represents a fairly meaningful 5% loss at our low North American automotive voltage of 12V. The drop across the diode is dissipated as heat (for the same reason your computer gets hot).

In the old days of halogen headlights and incandescent tail lamps (present day for Toyota peeps ), solenoid coils and analogue wiper motors, polarity was not that important, but voltage drop was critical to maintain brightness and reliable function, so losing 5% voltage drop for an irrelevant protection device was not a good trade off, so it was never a thing.

In these modern cars, I don’t really understand why they could not so least protect the sensitive electronics with a diode. That does strike me as bizarre.

 

I knew it was bad to reverse polarity when installing a battery, but i didn't know it was that bad... As always TW is a good and very informative site.. Thanks

 

*doesn't

 

Pretty nasty thing to say. The OP doesn't feel bad enuf already?

 

Best of luck today OP, I’m sure that you’re on the edge of your seat. Please keep us posted here.

 

You can also do it with a mosfet and avoid the voltage drop, but it's more expensive.

 

OP has left the building, probably by foot

 

Yeah you're right, i had to draw a picture. The deader the battery, the worse it is.

 

And this sort of crap, kids, is why I will NEVER buy a vehicle newer than 2005 or so.

Too much crap in them. To say nothing of the wiring harnesses which, if they aren't food for vermin, simply degrade until they are nonfunctional over time.

These aren't spacecraft, or even airplanes. There is NO REASON for them to be made so complicated.

 

I hope you never do valve covers on your 97 the engine harness is already decaying

I recommend getting a carb square body chevy

 

Plus the doner car will not like it at all too if you even get close to clamping that last cable.
Arc welding 101.

Good luck with that

 

If the OP picked up the wrong battery the connections might be on the wrong side making it easier to hook up backwards .