I was comming home the other day. Pulled in to the car port, got out and heard a humming sound. About that time my 10 year old daughter comes out the door and says my corvette is alive. Sure enough the sound I heard was from the blower motor for the HVAC unit. The car was turned off, not a key in it and the blower just started up running on it's own. The car is an '87 convertable with about 166k miles. I guess a relay got stuck or a wire shorted. I unplugged the connector at the blower and it stopped, but when I plug it back up it starts again. I thought I had seen a post on this before but could not find one when I searched.

Any experience with this kind of thing? Any ideas?

Any help is greatly appreciated.

 

If Electronic Air, Blower Module may have shorted to ground or the Fuse protecting the return signal to the Dash Controls has opened. Fuse is 5 amps and mounted on the firewall to the left of the Evaporator Case. Leads are either purple or black/red or whatever is hot at the Blower Motor. Module is mounted on the left side of the Evaporator Case. If the fuse is good, the Module is probably bad. It shouldn't have any voltage on the lead to the Blower Motor - purple or black/red - with the ignition off. Available at any GM Dealer or NAPA has a stocking number.