A4 Rear Wash/Wipe faulty

I have a 1997 Audi 1.8T Sport Avant with a fault rear wiper. Before it totally failed it did judder and I found that the teeth on the motor shaft were worn down and the wiper stuck in one position. Having removed the wiper blade the motor doesn't seem to function. I have a power feed going to one of the four wires, the Red and Black wire. There is not other feed from any other wire.

I do not want to purchase another motor if it's not that. I am not sure

if this has a relay or something else which may have failed. The fuse has been changed.

I would realy appreciate some advice as to the sequence of events to try and track down the problems. Should I be getting a feed from any other wire, if so which one and permanantly or intermittent?

Thanks.

If the wiper motor is the same as my passat the washer jet is fed through a pipe that is fitted into the shaft that rotates and moves the wiper arm. On my Passat the wash jet pipe, which should remain stationary, had corroded and had siezed to the shaft which meant that the pipe rotated with the shaft instead of remaining stationary. I noticed a fault with the system when I washed the rear screen and the jet of water moved with the action of the wiper.

Obviously the motor is designed to rotate the shaft only and not the stationary pipe I dismantled the motor assembly and using pleaty of WD40 managed to eventually free and remove the pipe from the shaft I then applied copious amounts of grease into the shaft refitted the pipe and reassembled the motor and all is now working as it should.

I guess if your motor assembly is the same design as mine the shaft and pipe have been joined by corrosion for a number of years which may have strained the motor and caused the teeth on the motor shaft to have worn down.