Use of battery terminal disconnect??

I want to install a battery terminal disconnect device (made of brass with a plastic knob on top).

Basically, it cuts off power flowing to the battery to avoid unwanted battery consumption/drain or theft.

Are there any issues with Toyota against such a use?

Reply to
maruk2
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On Jun 30, 3:14 pm, " snipped-for-privacy@hotmail.com" wrote:

I can think of one reason why it might not be the greatest idea.. Every time you cut the juice, you are going to reset the puter.. That means all of your drivability settings will be erased each time. Which means your puter will have to start all over with "base" settings until it's driven enough to relearn all of the sensor data, etc, and fine tune itself for max efficiency, performance, etc.. In this state, "TX" if you were to flush the puter by doing that, and then go to take an inspection, you would fail. Not enough drive data... You would have to run it through it's usual cycles to get some time, and see if any emissions problems, before they would pass it. But this is for OBD2 systems. I don't know how old your car is.. I don't think I'd want to do that myself.. The current drain when not running should not be enough to worry about, and surely there are other methods you could use for theft protection. Heck, just the immobilizer system in mine is going to make it pretty tough for most average car thieves. So I don't worry about theft too awful much on mine.. Heck, I wish I could disconnect the immobilizer system on mine.. I'm more scared of losing my keys, and me getting locked out, than I am a car thief being able to pick my ignition lock.. He's gotta turn that thing before it will start.. If I knew how to disconnect it, I'd be out there right now... I hate that thing in general. I also don't like being bent over for extra keys.. MK

Reply to
nm5k

Yes: NEVER operate that battery disconnect switch with the engine running, EVER, or extremely bad things can happen.

Without the battery in the circuit as a current sink and filter (and a voltage reference of sorts), the alternator can send some wonderful high voltage surges through the electrical system and fry stuff that can easily cost far more to fix than the car is worth. Like every lamp, all the electronics like the ignitor, the Airbag Computer, and the ECU/EFI Computer...

Other than that, no problem. Note that the car is going to run really rough for several minutes after each time you shut off that battery disconnect. The idle speed will be overly high, stumbling on acceleration and over-run coasting, etc.

The computer memory power is interrupted when you turn off the battery, and all the memory will be cleared, so the computers will go to "Failsafe" mode and have to figure out all the proper idle and mixture settings again from scratch.

If you can't park the car for two weeks without the battery going dead, you have an electrical problem that needs to be fixed. If the car will be sitting longer, it needs to be on a trickle charger.

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Reply to
Bruce L. Bergman

Also, an annoying inconvenience will be that each time you disconnect the battery with the switch, your clock will stop and your radio station presets will be (most likely) gone, so you'll have to reset your clock and put your presets back into your radio manually each and every time....a large PITA.

Reply to
mack

It will clear the OBDII computer every time you use it.

Jeff

Reply to
Jeff

To avoid resetting the ECU, clock, radio and other cpu controlled devices, you could look at the circuit diagram for, say. the ECU.

Most ECU's have a main +12v power that's switch by the IGN, and a standby power +12v input that keeps the ECU flash RAM active. Same for most radio's.

It would not be all that hard to set up a main +12v cut out as you want, and have a hidden, perhaps a small secondary battery that keeps necessary items live.

Sorting this all out is of course a PITA...

SD

Reply to
Stewart DIBBS

It would be much easier to put a switch that cuts off power to say the ignition or starter.

Jeff

Reply to
Jeff

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