Heater won't heat

Hello everyone, hope someone here can help me. I have a 92 geo metro. The heater has decided to stop heating...it actually would heat for a few, then turn cold, then hot agian, then back to cold....I took the heater fan out of my other 92 Geo metro (it worked the last time i ran the car) and installed it in the running one....I just changed the the round metal part that is facing the floor, the part is held on my three bolts...I figured this is the heater core....Am I wrong? Anyway....I got it all put back together, now all I get is cold air...
Oh ya, also when i took the one out of my good geo the rubber hose that connects from the metal part to the heater housing was clogged with leaves and twigs, but i unclogged it and to make sure the problem was more than just the clog I still changed out the part that I figured was the heater core....So am I wrong and the heater core is somewhere else and not on the fan, or could there be a worse clog somewhere between the engine and the heater....Sorry I don't work on cars that much so its hard for me to explain the exact parts I mean..hopefully you guys can figure out what I mean...Thankyou

Well, first line of business would be to make sure the heater core is even getting warm. When the engine is hot, feel the box that holds the core. Make sure it feels warm to the touch, or if you can take it apart, put your hand near the heater core. If it's getting warm, make sure your levers and such are all in place properly from the controls. They have a tendancy to fall off when they get old. If the heater core is cold, make sure the lines are attached to it under the hood. If they are attached, perhaps your heater core is plugged. Does the engine get warm to the point the radiator fan will come on?

I had the same problem and all i did was change the fuse to a higher one and it works ok. Also, if your car is in park or your not moving the heater starts to blow colder air. But once you start moving it works just fine. Hope that helps.

Well, first line of business would be to make sure the heater core is even getting warm. When the engine is hot, feel the box that holds the core. Make sure it feels warm to the touch, or if you can take it apart, put your hand near the heater core. If it's getting warm, make sure your levers and such are all in place properly from the controls. They have a tendancy to fall off when they get old. If the heater core is cold, make sure the lines are attached to it under the hood. If they are attached, perhaps your heater core is plugged. Does the engine get warm to the point the radiator fan will come on?


well thats part of my problem...i'm not sure where the heater core is or what it looks like.... and yes my radiator fan does come on....thanks for replying so quick...

I had the same problem and all i did was change the fuse to a higher one and it works ok. Also, if your car is in park or your not moving the heater starts to blow colder air. But once you start moving it works just fine. Hope that helps.


Your partly right.....if i not moving it just blows cold air...when I'm driving it switches back and forth between cold and hot...mostly cold though

Sounds like you've got air in your cooling system. Perhaps low on coolant too.

Sounds like you've got air in your cooling system. Perhaps low on coolant too.


you were right...low on coolant..all better now..i feel so stuid...lol....though after unplugging that line my heater blows harder now...so it wasn't a total waste of time

:cheers: glad I could help :)