I have a 1997honda odyssey van and my heat used to work so well i would have to turn it off every once in awhile and then one day I came out and it was blowing cold air, i changed the thermostat and still have the same problem

 

my cable came loose under the dash, havent got around to fixing it
so i'll be turning it off under the hood near the firewall pretty soon lol.

 

cool story