Probably just the one. Happened on my 1976 Honda. No big deal - dealer fixed it and it was not very costly.
Glad you are back on the road with a working heater fan. The heater in my truck isn’t currently working and I was quite cold the other night during a short drive, and the temps here in San Jose are a lot warmer than where you are. So I 100% understand why you needed that heater fan to work pronto. fyi, a blown fuse for the heater fan circuit could indicate the fan’s electrical motor is briefly stalling out for some reason. When it is powered up but not rotating the fan motor draws a lot more current, and that could well blow the fuse. At this point as long as you don’t hear any weird noises with the fan running, probably nothing else needs doing, good to go . But if the fuse blows again good idea to ask your shop to inspect the fan motor and blower cage. Leaves, sticks, that sort of debris can get sucked into the blower cage from its source at the air inlet vents below the windshield and prevent the blower cage from rotating, hence stalling the motor and blowing the fuse. I routinely vacuum that air-inlet area under the windshield to minimize the chance of that happening, lots easier than taking apart the dash to see what’s obstructing the blower cage.
Oh fantastic - something else to worry about!! Little by little I’m learning how things work under the hood. I will keep an eye on that fuse - it kind of worries me when only one fuse burns out. You’d think that they were all put in at the same time, so surely some others would die at about the same time. As it’s only one, I wonder if there’s something wrong with it. We’ve had an exceptionally cold winter this year - weeks steady at -25C or -30C, so the heater’s definitely been working hard.
Now I’m going back to the manual to see what and where the blower cage is ! Thanks for the info!
Normally the fuses last for the life of the vehicle, they don’t wear out. A fuse will blow when there is a short circuit or over load in a circuit. There could be a problem with the blower motor or the blower motor controls.
Each fuse supplies power to various and different electrical loads. So if the connection to one fuse is not making a good contact connection to the fuse leg then the other fuses should not be effected. When current passes through a bad connection that has extra resistance heat is generated at that point, and if it is bad enough, burn signs develop at that point. Your fuse is most likely okay but it might be a good idea to check it out after you have used the blower for a while to make sure things are okay. You can also touch the fuse to see if it is getting hot. If it gets real hot then there is a problem with the connection to the fuse.