LONGHORN1

recently i purchased a 01 is300 with 162k and im have a bit of ac troubles the motor and transmission were solid and the ac worked perfectly until earlier this week. before i was having the servo make the noises as others have reported for the cold/hot air mix door and that has stopped. I dropped the glove to see if i could see the servo arm move when i adjusted the temp dial and it does move when i adjust it from 65 to max heat. I also dont hear the compressor engaging but when i looked i did see water dripping from the orifice tube is that normal if the compressor isnt engaging? now i have read other threads and when i switch the ac button on and off it does not blink. now when the ac is moved all the way to 65 it blows very hot air. when i turn it back to max heat it seem to not be as hot so im guessing maybe the hot/cold door is maybe not opening all the way? second question is on the is300 i see there are two servos wich is the servo that controls that? the top or bottom? once i get home i will check the easy things like the fuse and try to maybe disconnect the battery to get everything to reset but any other advice will be greatly appreciated.

madassorz

your servo motor's gear has slipped out of place. very easy task but time consuming...

remove your glove box, remove the foot venting duct

there should be 3 philips screws for each servo, one of the servo is easy to take off, but the other servo closer to the firewall is kind of a PITA, I used combination of about 4 different screw drivers in various length[mostly short], flash light and mirror to aid me in this process. same goes for reinstall.

now the servo is off, take them apart by gently prying up on the tabs all around the unit. inside, you should see 3 white gears and 1 warm drive gear attached to the shaft of the motor.

the warm drive gear on the shaft of the motor has a drive gear at the bottom of it that spins the warm gear, you want to have that extended out so that when the motor is back in the servo casing, the gear does not have any play in it. I just left everything in the casing itself, aligned the warm drive gear and the drive gear, then pried it away from the motor to take off the slack.

here's a picture and a video on it.




good luck,

ps: I'd do this to both of the servo's reguardless, because chances are it will get stuck soon or later so might as well fix it while you are at it!

madassorz

was the problem ever solved??

lexusforce

I seem to be having same issue, it blows very hot air at the 65 degree location.
which motor do I need to look at how do I verify which motor is not working.

madassorz

take the glove box off the dash, turn the temp. dial and identify which motor moves/makes noise. fairly simple.

lexusforce

anyway I can manually move the lever to verify that it's slipped out of place. I don't hear noises and it seems to move as I move the dial, just don't know if it's moving right direction

madassorz

you'll want to unbolt the servo motor before you move the arms around to ensure that you don't brake any gears inside the servo.

the Top servo[the easier one to get to] controls the air position level and is connected to the top lever.

the bottom servo[hard and tedious to get to] that's next to the heater-core pipes control the heater core flap which controls air mix [hot/cold air].

but most importantly...seems like you haven't looked at it your self on your car just yet and trying to squeeze out answers that I can't diagnose...


^the one with finger pointed to is the top servo.


^and you can see both servo's in this picture. it's the black box with white circle plastic on it.



well...that should give you enough idea on how to fix this problem...IF the problem is the servo.

lexusforce

got servo out took apart looks fine no excess play. applied power to pins 6 and 7 motor spins reversed leads motor spins other way. Checked resistance on control pins out of car as I manually turned motor they look fine best I can tell. Servo probably not the problem. I am thinking now pcb related no control signals to servo or drivers out on the pcb.

Looks like I need to check control signals out of the control pcb.
Anyone know of a place to send board in to get checked out?

Thanks