1991 lincoln town car

[corey2225]

My 91 i replace the heater core about a month ago the heat blows hot but it only works when i put it on high and it doesnt blow very hard out the vents either. Can somebody help with a responce thankyou

[Towncar]

Assuming everything was assembled correctly

Sounds like two separate problems.. the air flow would be plenum doors not positioning correctly. The 'only on high' is the blower speed controller or wiring not connected properly.