Yes, if you get them backwards, you'll have AC instead of heat.....Just kidding. It doesn't make any difference.
This will not effect the engine in any way
Take the hoses of and run water backwards & forward through it.
If you look from the engine compartment you will see the 2 heater hoses that connect to your heater core at the firewall towards the passenger side
Basically behind and below the glove compartment , you can see where the heater hoses connect to the heater core at the firewall from the engine compartment
try switching the 2 heater hoses around, they may be backwards
loosen the clamp holding the hose on to a fitting and pull the hose free.
Try reverse flushing Disconnect heater hoses and try running a garden hose through in both directions.
From inside the engine compartment, disconnect the heater hoses from the core fittings located on the passenger side right next to the blower motor.........
On my 1995 Ford Explorer with 4.0 L OHV engine , where the heater hoses are connected right at the firewall , the hose nearest the driver's side is the supply hose to the heater core , and the hose nearest the pasenger side is the outlet from the heater core. (Helpfull)
could be head gasket problem. does your heater work? might need heater core , clogged up. do compression test. or bypass heater core and see if that works.
i think you might be talking about the heater hoses , if so it might be the heater control valve . the is a upper and lower radiator hose , but nothing should be between them.
Under air box hose .Right side of vehicle .Should have 4 heater hoses going to it and a small vaccum line .