Good morning, my 08 2.3 Ranger is currently having ac problems it works until i hit 60 mph after that it blows hot air or you'll hear it blowing but its not blowing from the vents. Any ideas ? I'm thinking its the blend door.

 

The vents, panel, defrost and floor are vacuum operated, Defrost is the default vent, i.e. no vacuum = defrost
So if panel air flow changes to defrost air flow while accelerating then you have a vacuum leak in the engine bay
There is a black plastic vacuum hose on passenger side of engine bay, it runs from the firewall to front rad support, to the vacuum reservoir, black ball, plastic hose can crack and leak
There is also a grey plastic hose for the heater hose bypass, they both go to firewall, often easier to find and follow grey hose to find the black hose
(these "look like" wires)

Blend door is electric, so can't see it being effect by speed, when system is working turn the temp **** and see if its working, for heat and AC
Blend door covers heater core, so in HOT setting all air flows thru heater core, in COLD setting all air flows around heater core, Blend door is covering heater core
The AC evaporator(cold part) in engine bay heater box, always has air flowing thru it, AC ON or OFF doesn't matter
Fan blows air thru evaporator first then to Blend door, and then either thru heater core or around it

Fan pulls in outside air, so if outside air is hot and AC/evaporator is not COLD then you get hot air
MAX AC setting closes the Outside air vent, so fan pulls air in from the cab, it also activates the grey vacuum hose and closes the heater by-pass valve in engine bay, so no HOT coolant flows thru heater core

AC has two pressure switches, high pressure switch prevents hoses from blowing out
Low pressure switch prevents compressor from burning out

As compressor speed increases and with long term use it may be pulling in "freon" faster than the system can provide it so low pressure switch "opens" which cuts power to the compressor to prevent burn out
Check "freon" level in the system
Could also be partialy blocked orifice tube/expansion valve, not letting enough "freon" flow thru to maintain high levels in low pressure side, this can be tested for with pressure gauges

 

What's the best way too repair a cracked or broken line ? Turns out a line broke coming up from the black ball.
Its always something with this truck.

 

Just cut out the bad part and replace with rubber vacuum line if correct size

Cut out the bad section, take it to auto parts store and get section of rubber hose thats a snug fit, no clamps are needed its Vacuum so won't push apart, is sucks connections together

 

Where could i get a new line ?

 

Don't need one

Take/pull that end off and cut off a section of hose, then go to auto parts and they will have adapters, to connect smaller hose to larger port

Or hit a wrecking yard and get that rubber fitting with longer hose attached, so you can splice with short rubber hose, doesn't need to be Ranger or even Ford these plastic vacuum hoses and connectors are just way cheaper than the rubber hoses so all car makers use them now.