The motor only runs when it gets power. If the motor runs, why would you expect a new one to work any differently? You need to determine why the motor is getting power when it shouldn't.
The motor runs when it gets power from the body computer. The body computer turns it on after interpreting the command from the multi-function switch. This system has been turned into a very complicated system by adding the unnecessary, unreliable computer.
It is extremely common for the body computer to cause the wiper motor to never run accept when the washer switch is pressed. The second most common problem is intermittent unrequested operation of the wipers due to the turn signal switch. The problem was caused by the supplier that made the switch for Chrysler. It actually has three part numbers. One is for Chrysler and one is for Toyota. Not sure who the third one is for. There are different value resistors in the switch. The body computer reads the various resistors to determine which delay setting you selected. At times the computer misreads the resistor and thinks you're requesting the slowest delay setting. The symptom is called "phantom wipe". Your dealer's parts department will likely still have a bunch of new switches in stock. They were a very common problem.
Earlier models had a problem with the wiper motor that would cause it to short internally and blow a fuse. In that case, it would never run at all until it was replaced.
Saturday, January 16th, 2010 AT 5:42 AM