Q: My windshield wipers won't turn off on my Cadillac CTS 2005.

The switch contacts are welded (stuck) shut OR the circuit is being powered due to a wiring fault or some sort of short. It is also possible that relay contacts in the wiper circuit are stuck on, regardless of switch position. Sometimes micro or solid state relays are used, so when the circuit trace is performed an actual circuit board might be implicated in the fault you are describing. Regardless of the cause, if you request an electrical component diagnostic, the responding certified mechanic will use the vehicle wiring diagram (Factory Service Manual) and simply trace the circuit to find out where the power is coming from and why the circuit does not shut off when commanded. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.