1995 EATC blower runs when I turn the key off. (1 Viewer)

[Kane]

I put my ShBoom in the garage the other night. When I went over the next day to get it out again, I heard the "noise" in the garage. I couldn't figure out what it was. I went to start the car and the battery was almost dead. Turns out the "noise" I heard was the blower motor running. It turns on when I turn the ignition key off!. I dropped the glove box out of the way and unplugged the blower. When the key is on, the blower operates as it should!
I replaced the "Blower Motor Control Module" and that didn't change it. Please see attached pic of the old one.
This is a 95 with the Electronic Automatic Temperature Control HVAC option.
Thanks in advance. I'm an old guy and not very good at this electronic stuff!
Kane

 

[74 Harley]

Look in your fuse box for a relay that controls the power to the blower motor, it may have gone bad.

 

[Kane]

Thanks for your reply. I'm trying to figure out how if the relay went "bad" how it would supply current when the key is switched off? Told ya'll that I'm not good at this electronic stuff!
Nice 62 you have! I had a 60 that was a similar color! Takes a real man to drive that around!
Kane

 

[74 Harley]

The job of the relay is to use low draw current from the ignition switch to operate the relay, it supplies higher amperage to whatever accessory it is operating.
Essentially the relay could be stuck in the on position.
Thank you for the compliments!

 

[Kane]

Thanks for the replies and attempts to help
Here’s what I did. I replaced the blower speed controller (PWC) unit (new part) and that didn’t fix it. I then replaced the ignition switch. Now, to date after approximately 50 “starts and shut offs” it hasn't acted up. I plan on installing a small (1/4 “) LED Indicator Light (in series with the power to the Blower Motor Speed Controller) somewhere unobtrusive so I’ll notice it right away if it stays lit when I turn the key off.
Thanks again.