heating problem plz help

[caaguy]

i drive a 2002 s-10 4.3L my heat hasent worked for about a year now its getting cold out and i need heat so my cool air and a/c works perfect when i turn the dial you can hear the change of air movement but still no heat. Now i have a heater in the back of my truck to keep my tools and batterys warm the heater is a 12volt heater and the heat is fed from hoses from under the hood and it works fine i have no clue what it could be i did have coolant problems before where i would have to fill it every month. i pressure tested the system and found the leak in a hose which i repaced problem solved but i still got no heat. my guess is the actuator isent moving all the way or my heater core is pluged.. other than that i dont know what to do please help thanks Thomas .....caaguy

[16th hippy]

if you can hear the door moving as you turn the knob then would start with heater core clogged. get truck to operating temp, and check the 2 hoses going to the bulkhead(firewall)..if one is hot and other is cold, clogged heater core, if both cold no water even getting to there, start looking for clog in hose at water pump and so on. best of luck, let me know how it goes.