If only the HIGH SPEED is giving trouble but not the other speeds, check the HIGH SPEED relay mounted on the firewall facing the engine on the passenger side, they burn out easily If all speeds are giving trouble could be the power source or the blower motor
Most likely cause is a failed blower resistor.
could be the resistor on blower motor is bad
Check ignition switch
A front popping on the left of a 98 Blazer could be the brakes, steering, or wheel bearing. Check all three to find the cause.
In the engine compartment near the A/C evaporator box, closest to the inner fender.
Typically a relay or resistor. But could be a blower switch or blower motor problem.
Fuel pump could be possibly getting weak. Happened to my blazer.
There could be two separate problems. Check the blower motor resister, and the ABS sensors for problems that could cause this.
Could be a blown fuse.
Yes, it could.
Check to see if any of the air intake pipes/tubes have come off or are loose.
What that could be is diaphragm pain. Most people don;t realize that their diaphragm is really a muscle and it can get sore or go into spasm, like other muscles.