I installed a new ceiling fan/light combo. I have two wall switches. (one for fan, one for light). I don't want a remote. I did not use the control box(remote operated brain box) that came with the new fan. (fan is Harbor Breeze?) Instead, I wired one switch each directly to the fan and light respectively. Everything works fine, but I forgot about fan speed. How can I now adjust fan speed? (3 speed or otherwise)
Fan model is important here, some of the fans can't be controlled without the electronics you intentionally removed. Why did you do this?
You can't place a fan onto a standard dimmer switch because it damages the motor, your only option is to research the fan model (or call the company) to determine if you can place a fan control switch in the wall to regulate the speed. Unfortunately this isn't always an option and it's becoming more and more difficult with "smart" technology they are incorporating into basic devices. If you don't want the ceiling fan connected to the home Wi-Fi and don't want to use an app to adjust the speed and turn it on/off then you're SOL with certain models. Not very smart but who am I to judge...
My advice would be to install the fan control which came with the unit and it solves the problem without extra costs and labor. Adjusting the fan speed is something I rarely do in my home so I just chuck the remotes into the kitchen cabinet... With certain models you can also program them to use a single remote and eliminate the need for multiple devices.