This is a bizzare problem that I have not encountered before and I am not sure if I can be of any help.
I will try to get other techinans to assist and hopefully wre can come up with something for you.
In the meantime, let us get to understand the situation better and hope we can do some testings to see if we can resolve the problem.
Here is a description of the intermittent wiper system.
Intermittent Speed Windshield Wipers
The intermittent wiper speed is activated with grounds controlled by the multifunction switch inputs to the windshield wiper motor module. The windshield wiper motor module then activates the windshield wiper run/park relay coil and switches voltage through the windshield wiper high/low relay. The high/low relay remains deactivated supplying the voltage to the wiper motor low speed input and activates the windshield wiper motor. When the windshield wiper motor module receives the grounded input, the motor continues to operate until Hall effect senses magnet to turn off run/park sense the output to the windshield wiper run/park software, deactivating the relay and disconnecting voltage to the wiper motor. The windshield wipers remain parked until the windshield wiper motor module completes a time-out and then repeats the intermittent windshield wiper cycle.
From the description above, one of the possible cause of the lurching could be due to a bad ground circuit for the intermittent wiper mode and it is draining the power supply or ground connections for the ignition switcch or engine controls.
Check the ground circuit connection from the multifunction switch t see if it is loose or contaminated.
Friday, January 8th, 2010 AT 10:47 AM