Breaker of fuse?
I'd like to see a photo of your installation.
If you are going to all the trouble of removing your dash, I would take the opportunity to make those 3 relays more accessible. A simple task with eh dash off or almost off. Be extra careful if you disconnect the
oil pressure line. There is a tiny ring that can easily get lost....While you’re in there, examine the blower. Look for a schematic and other wires not being used...if you find any I would like some photos and a detailed description. Someone said that the motor may have multiple speeds, just not wired....Thanks