Hi guys, I have a 1990 Honda Accord DX, bought it from my friend, well the air/heat system is messed up, I only have heat coming out of one vent, the other 3 are cold. Well my friend told me that theres a switch under the hood that I push or pull or something that either turns the heat on or the air on, but he says he will have to show me because it cant be explained.. I have a little knowledge of cars, not much... is anyone familiar where this is or ever heard of this?