Defroster WON'T turn off

[300Z2+2]

Hey I'm new to the forum and have a 94 300zx 2+2 NA. Well basically a few days ago when I left to go to school I turned my defroster on and it wont turn off ever since. My car does have the auto controller. I have plugged in different relays tried my fuses and even put on a spare controller I have. I had the thought it might be a vacuum leak but I am at a loss.
Any help would be appreciated. Feel like I should minor in electrical engineering after tracing all these diagrams....

[t.mcginley.jr]

It sounds like a relay got stuck, but you said you tried them all? And I suppose its not the controller if you tried another known good one. Possibly a bad ground somewhere but I wouldn't know where to start looking.

[300Z2+2]

Yeah I know the only way to get it to go off is to pull the fuse. Yeah I switched out the relay for it and still the same. I guess I can check voltage in the connector going into the controller... Great to have a hard copy manual I must say.