I have a 2002 Grand Caravan Sport with a 3.8 liter engine. The heater blower works, but the heat won't always get hot. Sometimes it will blow hot, others, it blows cold. Am I correct that if the heater core was bad, it would always blow cold. Any suggestions as to what to look for?

 

You might want to check out the thermostat. I had a truck that the heater never got past luke warm. Turned out the thermostat was opening to soon. Check your coolant level also.

I had a pin hole in a heater core once. Only noticed it because a film built up on the inside of the windshield from coolant being blown on it during defrost.