I’m an electrician by trade but i have a friend who needed his blower motor replaced. The parts store sold him a motor but it only has one hot leg. The control board has a hot for cooling and a hot for heating. What would happen if I wired them both together to the hot for the motor? I’m afraid back feeding the control board might fry it? Any suggestions would be appreciated.

  • 1
    How was the old blower motor connected? – manassehkatz-Moving 2 Codidact May 20 '19 at 18:01
  • Had a hot for cooling and heating. It’s an old unit. – user101844 May 20 '19 at 19:09
  • The original may have had different speeds for heating and cooling. Running at a single speed may result in other problems, e.g. icing the evaporator. – HABO Feb 10 at 20:31

It'd be fine, simply because I can't think of a 120 volt AC relay that would be damaged by getting back fed power. Mechanical and solid state can both handle it as far as I know. That's not a 100% you're good though, maybe 90+% confidence?

Worst case it passes current backwards through to hot and won't be able to shut itself off, but you'll catch that during testing. Nothing should blow up.

  • 1
    That’s what I was thinking Ok thanks for your thoughts and your time. – user101844 May 20 '19 at 23:48

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