1994 Ford Ranger Heater problems.

1994 Ford Ranger 3.0L V6 4x2 60,000 miles, manual transmission. Heater is not working. Replaced heater core, thermostat, gasket, coolant and heater hoses. Question is what can be the possible problem if not any of those and if, let's just say for example, I connected the heater hoses (the ones that attach to the heater core) incorrectly does that really matter. :oops: Anyway what is the correct way for the heater hoses to be connected? Is it the left outlet (looking at the engine from the front of the vehicle) of the heater core to the water pump connector or is it to the thermostat connector. Which one goes where? Like I said before I don't know if it really makes a difference but if it does can someone please give me some guidance? And no, I am not really a mechanical type guy. Thanks for your help in advance

Luis

P.S. I have the Haynes repair manual but it's not really much help.