96 Chrysler Town & Country main heater troubleshooting

We have a 1996 Chrysler Town and Country 3.8L, at first the heater would
stop working if we hit a bump, was occasional didn't always happen. Then
would start back up if another bump was hit. Tested for shorts in wires,
checked the fuses etc...and got nowhere. Then when we would shut off the
vehicle the fan would still be on and we would have to put key back into
ignition into the on/start position and use the on/off dial to shut it off. And
once we did that it was fine. However, just as luck would have it-just as
winter was coming, heater completely stopped working. My husband again
tested everything he could think to test with a meter, came back with nothing.  
We decided to again go checking the fuses again, then just went ahead and  
replaced the resistor, the blower motor, and even got a different...Still
nothing... He ended up temporarily taking it straight from the battery to the
blower motor. It works but only at low speed, but it is not producing enough
heat for winter or having to go anywhere with children...It is a manual temp
control with the driver and passenger side settings. We also got a new main
power wire that hooks up to the resistor as well. Resistor, both the new and
old blower motor everything tests fine but its like there is no power when its
hooked up...We are not sure where else to go from here...Any suggestions
would be greatly appreciated, thanks in advance.