98 Plymouth Voyager Front heater problems!

I have a 1998 Plymouth Grand Voyager, with a 3.3 liter MFI, engine, with 187,000 miles. I recently purchased the van, and it is in good running condition. The front heat did not work when when we got it. The rear heat is working fine. I replaced the radiator, thermostat. I also seen a crimped heater core hose, and replaced it also, but it still didnt fix the problem. The heater core does not leak.
On the control panel, nothing lights up, except the top 2 rear windshield wiper buttons, which blink on and off continuously. The rear blower switch works fine. The vent switch works, adjusting from, defrost, to front vents, etc. The front blower switch only works on High and none of the other speeds seem to work.
So, I have 2 different questions.

First what could be the cause of having no heat in the front?

My second question is, how is the heater hose system ran? Example, does the heater core hose run into the front heater core, and then out to the rear core, then from the rear core, back to the front, or are they ran on seperate line systems?