Got an 01 f150 excab with the 5.4 as of lately sometimes when i turn the 1-4 blower control know it wont do anything on heat or ac than other times it will work like it supposta and one have this problem or any answers thanks.

 

101, no problem, it's just like me - retired. Couldn't resist! Hmmm, have you checked the GEM under dash behind fuse box? They can cause strange issues.

 

blower motor speed is controlled by a series of resistors on a resistor block. if one goes bad, you loose 1-2 or all speeds. If this is intermittant, i would guess bad ground or corroded power wire.... check the block under the glove box for bad wires. block is on the hot air duct.