Q: Heater run after key off on 1994 Buick Roadmaster

Rookie cbe0621eac06868b3efe0d8d1d3611e23c60d3114864ea2ec19a68cfbd3eebab
94 buick roadmaster with auto climate control Blower runs all the time will speed up and down with key on but will not stop even when key off checked grey black wire at blower resistor has low voltage after key off. no relays under hood for hvac. only relay by blower motor is for rear defogger. where would the relay be located.
(1) Answer
First, make sure that you ignition key is not shorted. Then if the motor speed is erratic when on or off, then I would check the fan speed module. I recommend going to and paying for a 1 yr subscription to the factory service info for your vehicle. Here you will find trouble shooting trees for your electrical systems. Most Pro techs use factory spec manuals and wiring diagrams to accurately trouble shoot problems, other wise it becomes a 'dart throwing' contest.