'93 90S heater problem

[HRDDOUGHTY at aol.com]

I was driving in to work this morning, and I had the heat on, all of a sudden i notice the air is coming out cool or almost cold, so I shut it off, then a few seconds later I hear this rattling noise coming from just behind the dash or inside the vents, it lasts about 5 seconds, then a minute later I turn the heat back on and it works the rest of the way, no problems.....any ideas??

An email from my son this morning. Help would be appreciated.

H. Reed Doughty
hrddoughty at aol.com
LeClaire, IA

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