there are resistors in the blower motor itself
Chevrolet Tahoe rear blower relay switch can be found behind the dashboard. The relay switch will be behind the drivers side dashboard.
If there is current going through the wire to the blower switch, try bypassing the switch with a jumper wire. If the blower motor works, then replace the switch. If the blower motor does not come on, then you probably need to replace the blower motor.
The 1989 Honda Accord blower motor relay switch can be found on the firewall in the engine compartment. The blower motor relay switch will be on the passenger side of the firewall.
The 1995 Ford Explorer blower motor relay switch can be found in the fuse box. The blower motor relay switch will be in the third column, second from the top.
Check to see if you are getting power and ground to the blower motor - if so blower motor is bad. If no power possibly fan switch or selector switch Also check the blower motor resistor, found in heater plenum.
tested blower,ok. then tested incoming voltage to blower and found to be zero. the final step was to replace the blower switch. To replace that switch, the middle part of the dashboard, including the radio had to be removed. The ac and heater come in one piece. It worked fine then. I think, there is a chance that the switch could be just cleaned up and it would work, again I think.
You didn't mention what year S10 Blazer you have but, the blower motor speed resistor can be found under the hood, on the passenger side of the firewall, close to the blower motor.
Not knowing what year S10 you have, you can generally find the blower motor high speed relay nearby the blower motor on the firewall. The resister for the other lower speeds is also found close by the blower motor.
The 1973 VW Beetle low beam switch can be found on the drivers side floorboard. The low beam switch will be all the way to the left of the drivers side floor.
The backup light switch and the brake switch are all in the same relay switch. The backup light switch can be found beneath the drivers side dashboard.
Blown fuse, defective blower motor resistor pack, blower motor, or blower motor switch. This happened to me and I found a connector at the fan motor had fried. I changed the connector and it worked great.
The brake light switch can be found below the dashboard on the drivers side of the passenger compartment. The brake light switch simply plugs in and out.