GMC Troubleshooting Questions? Ask a Mechanic for Answers
Hello, my name is ***** ***** I am a professional here at Just Answer. I have noticed that your question was not getting a response and thought I would see if you still need help with this.I apologize for the delay and I hope I can still assist you with this here.The place to start is to check the voltage at the switch with it in the normal positions, see the test steps in the link below. Copy and paste the link to your browser to open and view the steps.https://dl.dropboxusercontent.com/u/104923897/Selector%20switch%20Dec%208.pdf
If you are having to modify the switch by removing the springs then I would suspect the switch is defective especially if it runs with them removed.
Well at this point I am out ideas, if you would like, I can open the question back up and hopefully some else may have something new to add. Let me know.