Jeep Repair: heat problem 1997 jeep cherokee, jeep cherokee, heater core

Question
QUESTION: the heat will come on warm for a short time and go cold does not blow at all on high speed.

ANSWER: possible heater core is clogged .Thermostat messed up.

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QUESTION: how to tell if your heater core is clogged. and if it was would it ever plow hot or warm air//// Thanks

ANSWER: warm up the jeep and feel the 2 lines going to the firewall  if one is alot colder then the other  u have a  clogged core.
It will not work again until it is cleaned out or replaced.

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QUESTION: thanks i will try that,any suggestions on how to clean if needed????

Answer
most of the time a coolant flush might fix it. If u want to do it yourself take off both hoses and run water through the heater core and see if it will push any stuff out   if not  no choice but to replace it if u want heat. I will be fixing a heater core in a few days where I am at.