Q: no heat from front vents, rear blowing cold air. Blower motor relay, resistor, blower motor, temp control panel all ok

There is no heat coming from the front vents on any speed. Rear vents are blowing cold air. I swapped out the resistor with a used one, no change, both resistors after being removed we're hot to the touch which leads me to believe they are both good. Jumped the blower motor and it came on at high speed, swapped out the temperature control panel with a used one and no change. Heater core tubing is hot to touch at the fire wall. I swapped the blower motor relay in the fuse box under the hood and the "run" relay...nothing has worked, still no heat. I checked the blower motor fuse (#42) and it appears in working condition. I have only had the vechicle a few weeks and the heat went out within the 1st few days, And I have not been able to drive it much without the heat. What else could be the problem here? Are there other fuses that could be bad? If so which one's should I check?

My car has 158000 miles.
My car has an automatic transmission.