I have a 98 GS300 and need help diagnosing an issue.
It all started when I lost the A/C one day. Probably due to the compressor locking up because of low A/C coolent pressure. The serpantine belt started sqeuking and such so I turned the A/C off. Drove around for a while and then noticed that if I turned the wheels while sitting still the serpantine belt would lock up, my "battery light" would come on because the alternator would stop rotating, and the power steering would go dead! Then, even while driving, the power steering would lock up and it became dangerous. This Lexus is not like my Subaru where you can run without power steering, and it will eventually wear out the alternator and PS pump if the belt keeps slipping.
Now I know these are all due to the belt locking up/slipping, so I went to the store and bought a new belt, thinking it would help the slip, and installed it. Get in the car, start her up, and turn the wheel but AGAIN the belt locks up under power steering pressure. I have the A/C turned off so that pulley is spinning freely, the alternator spins easily by hand, but something is still locking up the serpantine belt.
I have another car to drive, but I really want to solve this problem!
My next step is to have a buddy sit in the car and move the wheel while I apply more load on the tensioner assembly (and belt) to see whether or not the tensioner needs replaced.