my window washers don't work at all and light washers work only part of the time, i can't even figure out which fuse is allocated to the washers

any advice?

by the way how bloody incredible are GS model lexus!

 

Most of the time the problem is the pump motor in the bottom of the washer fluid reservoir.

You will need to access the motor, unplug the connection and check if 12 Volt or more is across the plug connection when the switch is activated.

If not, there is a fuse blown. This occurs when the motor freezes.

The motor is held into place with a clip on the bottle.

 

I take it you know the lights have to be on for the headlight wasshers to work?

 

correct, the lights need to be on.