Toyota Repair: 97 Tacoma Heater, control cables, temp gauge

Question
My 97 Tacoma 2.4L 4cyl heater has very poor heat output. It does produce heat, just not as much as I would expect. The temp gauge reads normal-middle of the range. The coolant is Toyota brand and recently replaced. What could be the cause?  Is this normal? Thanks.

Answer
Check the heater control cable under the right side of the dash, it opens and closes the blend door to let heat in, they have a tendency to come off so check for that, check the control cables under the left side also make sure all are attached, make sure the heater valve moves all the way when moving the control lever, if it's none of the above I suspect the heater core may be partially clogged.