I have very low heat from my 2001 Grand Cherokee.
There is heat but its doesnt get hot. Anything under 18 degrees, we freeze! Otherwise its
ok, not hot though. I have replaced the blend doors with aftermaket product, which has
failed. I disconnected the motor and taped the doors open for heat. Had mechanic check
fluids and its all good. It does not over heat and heats up to temp. I had someone
suggest it might be one of the vent door not opening properly. What would cause this?