Any Toyota / Lexus tech's here?

[Fordum]

On most cars this can be avoided by using a little device that plugs into the cigarette lighter and has a 9 volt battery attached so that when you remove the vehicle's battery the memory in the ECM is retained and doesn't have to relearn the idle and or driving habits.

Don't know why I didn't reply to this back when it was posted, but I often have problems figuring out why I put on the clothes I did in the morning, so...........

4X4HIGH is right about that.

But, you need to buy a ready built one if you can.
I have seen folks just wire a 9 volt battery into a lighter plug. You must put a diode in series with the battery.
Otherwise, the 12 volt car battery starts charging the nonchargeable 9 volt one resulting in either having to put out a car fire, or clean up little bits of 9 volt battery out of your hand and parts of the car.

Also, the trick does not work if you have a heavy load turned on.
IOW, if you leave the doors open so that the inside lights are on or turn on the headlights while just the 9 volt is in there, it will run it down or suck it's voltage too low to maintain the memory in seconds.

 

[chalet2506]

There are only a few reasons for an Alt. to put out that low voltage.
Main causes, roughly in order....
1: Bad Alt.
2: Load bigger than it can handle, often a shorted battery cell combined with heavy regular loads.
3:Loose or bad connections.
4:Loose, glazed, or otherwise compromised fan belt.
5:Really low idle.

No. 4 used to be No. 2, but with serpentine fan belts and spring loaded tensioners, its not too common anymore.
If you were able to hold the tensioner back with one hand while you put on the belt, you are either a heck of a lot stronger than most folks, or you need to replace it.
Same if the belt has no ridges in it anymore.

Otherwise, you should have taken care of 1, most likely 2, and most of the 3s that would be likely to cause problems. And 4 would have been pretty obvious.

Sometimes shotgunning a problem is the best, but its just not as satisfying........

This my guess. Alt going bad or voltage regulator on the fritz. Battery wasn't that old, but I expect 3 years out of one. We just came off the coldest winter followed by the hottest summer here in a long time. Might have been a bad cell in it.

Stinkin alternator was $199, what the hell do they build them out of these days?

 

[Fordum]

Copper and silver prices are really high. Don't know if there is any silver in it, but it shows up in the strangest places in electrical work.