Pontiac Repair: 2003 pontiac gran prix windshield wiper problem, pontiac gran prix, windshield washer

Question
QUESTION: My windshield wipers will not work. in delay or low the motor just hums and if switched to high or if you try to use windshield washer function the radio quits and the power windows quit. If left in delay or low eventually the same will happen. Have replaced the motor twice to eliminate and have replaced the drive arm trans and aligned properly. This problem will occur with just the wiper motor plugged in without any thing attached. Never blows the fuse ( 25 amp ) for the wiper circuit. Have not replaced the multi function switch on the column. This is a 2003 pontiac gran prix with 3.8 engine. loosing my mind on this one. Any suggestions or answers would be appreciated very much.

ANSWER: Hi rick:

this has an issue with a bad ground connection. there is a ground wire on the innder fender area under the master cylinder area. that gound is for the wiper motor. the fact that when you turn on the motor and other things quit means the wiper motor is searching for a ground that is bad and backfeeding though other ckts in the car. good luck :-)


---------- FOLLOW-UP ----------

QUESTION: Todd, thank you for your time and advice! Let me update you. I had previously grounded the wiper motor case direct to battery negative with no fix and at your suggestion did it again and motor will still not work. then grounded the black wire at motor connection direct to battery negative. no fix. unplugged motor wire connector & checked voltage across plug with wipers on low. 11.2 volts with ignition switch on & headlights. this was checked between yellow wire & black and also green and black. Pin connector looks good. have used 2 different replacement motors which are rebuilds by a popular co. Bench tested the motor by applying bat voltage ( 12.18 volts ) to yellow & green with negative pin grounded and the motor worked fine and in fact even parked the shaft.  found the body ground on the RH side of the car and cleaned with no improvement. Will a 1 volt drop cause this issue? I am sure with the car running and charging the reading ( volts to wipe motor) would be higher even though i did not check. If anything stupid & different can happen in this world it is to me. What do you think now? I am back to the multi function switch which is $366.00 at our local Autozone store. Your thoughts appreciated!!!!

Answer
sounds like you have a switch issue here. but then again with out seeing it I can't tell you for sure. I can tell you any kind of a voltage drop can cause all kinds of issues. I would double check all you ckts before you drop the $ on a switch. check from the plug at the motor to the connector at the base of the steering column. if you have no excessive resistance and you ground is indeed good then I ould go with a switch. I can tell you from experince that I do not trust rebuilt/reman eletrcal parts especially if they are "cardone" brand :(