Exhaustgases

A museum car that has no options? That makes no sense.

What is posted makes no sense. If it truly engaged in all gears then it would be going or moving in them all. You need to check for codes, and I think you meant all selector positions work while the car is sitting.

I discovered that the Idle air control motor bearings go bad and start to seize up and that causes all sorts of problems with idle and such.

Absolutely DO NOT CLEAN THE AIR METER. You will ruin it. $700. for a new one if you can find it.

Since yours is a 96 with OBD2 then yeah it would work.

Sorry didn't notice the year before. Any transmission shop will not spend the time to trouble shoot the problem, well maybe one out of 100 or so would, most of them just immediately sell an overhaul or rebuild, it makes more money than just a quick fix does. And some sneaky ones will sell the rebuild and just do the quick fix. Its difficult to find honest anything automotive fix it places. So its worth trying to change the fluid and at the same time check the solenoids, use a new screen and put the correct amount of fluid in. I'd check continuity of the solenoids and they could be quick triggered with power and also the wires as well as the selector switch should be checked.

Or idle control motor bearings seizing up.

And in a year or so when you have transmission trouble, it will be from that fluid that was used.

Wow a nice way to over charge for a cheap part. Even the whole base plate should not tip the scales more than $50. Please keep this updated if you find the part cheaper some place. I have a question so if that relief valve pops off does it just release the refrigerant? I don't think the pressure should go higher than 150 psi

Something else that degrades and has a recommended replace interval is the O2 sensors. And if you go to the clublexus site there is a good bit of info on the idle air control motor bearings that can cause some major drivability problems.

What year car? And if the transmission was serviced along time ago and the wrong fluid was used now its showing up the not using the correct fluid. There is no one size fits all automatic transmission fluid when it comes to Lexus and Mercedes Benz. Its just not worth the experiment to use the wrong stuff.

Likely they are no longer available.

And most important what year of LS400?

So then the explanation was not very accurate then. And not electrical in nature, you should have said the wiper motor was running but the wiper on the diverside was not moving. Glad you got it sorted out. And for others asking for help, remember with out accurate descriptions of the problems us people trying to help can only guess. We do not see or hear the problems.

Check for power at the motor, when the switch is turned on. I don't remember if there is a relay for it and its own little ecu these cars seem to have lots of them.