my heater only blows on high---how do i remove the panel behind the controll *****. thanks for any info------------r j f

 

Sounds like the resistor pack that controls the ventilator fan speeds burned out. When you use fan speed switch, it selects a different resistor for each setting. Highest speed is just a wire, lowest resistance. The slower speeds equate to a bigger value of resistor to dissipate power and slow the fan speed as a result.
Over time, condensation builds up in ventilation system and resistor pack corrodes; eventually the connections open up and you get your only runs at full blast problem. Replacement part is $20-$25 from a dealer. It's an easy fix.
Resistor pack is accessed from under the hood. Facing truck, ventilation fan motor is on the left hand side of the firewall. Look at the wires that run to the fan motor, down near the bottom of the motor where the wires enter, you'll see a small plate with a couple of retaining screws - it's like ~1.5 inches by ~3 inches. The resistor block is located inside there. With your new resistor block in hand, verify the correct orientation, and take wires off of old block and put on new block on at a time. Then re-install it into the blower housing. Fan should work on all speeds now.
The only other problem could be is if the wire connectors are corroded beyond repair, then you'll have to do some surgery to replace them.

 

I was thinking of the other end at the **** controll. I pulled out an old cb cable and think I might have pulled off some wires on the controll. So I want to take off the controll **** and back plate to see if I can check the conections on it. I can free the bottom part of the plactic trim but can't free the top part and I don't see any thing holding it. I don't want to break the plactic if I don't have to. But there must be some screws behind it to hold the back plate onto the dash.