ac blower fan blowing fuse

[phillipsweek13]

84 blower switch has 4 speed blows on first 3 speeds blows 25 amp fuse on hi speed

 

[ecss]

84 blower switch has 4 speed blows on first 3 speeds blows 25 amp fuse on hi speed

Remove/unplug the Blower relay.
Try the Hi setting.
If the fuse doesn't blow, the relay is bad.
Also take a good look at the wires of the relay socket.
Verify the wire insulation hasn't shrunk back allowing the wires to short together.

Picture of the relay location. Under the hood passenger side of blower motor.