Does anyone have an idea of why the fuse would fail to blow when the belt got wrapped around the fan shaft?

It fried the fan motor, the plug for the fan motor, the relay and melted the relay socket a little, but the fuse remained unharmed. It was pretty strange by the fan not moving, it heated everything up, but not enough the blow the fuse.

I wonder if I could put in a slightly smaller fuse without it blowing during normal use to lessen the probability of this happening again?

89 Cam Cam with single fan.

 

A stalled motor draws more current than a turning one.

 

What value did the fuse have? It is unusual as this is precisely what the fuse is there for. Yes, you could try a smaller fuse, it will have to be large enough to handle the start up current of the fan. You could measure that and the current when the fan is stalled and choose a fuse somewhere in between.

 

It has a 20 amp fuse if it's the one for F/P-FAN-C/H.

I'm also going to look into an inline fuse for added safety. I need to solder the wires with the new plug anyway, so it would be the best time to do it. I am temporarily using wire nuts. I have a soldering gun and heat shrink tubing, but need to get more solder.