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Discussion Starter #1
It was really cold this morning, so when I started up my 76 sedan deville and drive her I put the climate control all the way over tothe red and set the switch to auto. After 10 minutes it wold usually turn on and blow, but it never cam on, no heat at all. What could this be? Could it be a sticky thermostat? Any sugestions?
 

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13 Challenger RT, 11 CTS Coupe Premium, 94 Eldorado (RIP)
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A thermostat isn't going to cause your heater to not work, as long as the engine is warmed up. If the blower isn't blowing, you need to check it out. The blower motor may have crapped out.
 

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'80 Fleetwood Coupe, 1994 and 1995 Mercedes 140 Coupe
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If the blower she ain't blowin' then easiest first thing is to check the engine block temp switch located on the cylinder head. IIRC it is on the pass side. It will have a single spade terminal. Try grounding the terminal (wire side) and see if the blower starts. This gizmo is there so the fan will not blow cold air on you until the engine warms up. Then it will blow heated cold air.
Your problem can also be a half dozen other things but this is a place to start looking.
 

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1979 Sedan deVille d'Elegance
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Hello!

I will second what the Ape Man says. My '79 deville had a problem that sounds just like what you're experiencing and the $8 part on the side of the engine block got the heat coming out!

Good luck!

Dave
 

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Discussion Starter #5
I will try that, but I did notice the "always on" fan near my feet is still running, it just wont fire up to bloe hot air hi, it just blows very low as in the always on position
 

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1979 Sedan deVille d'Elegance
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Hi!

I had two postings recently about climate control issues. The first one dealt with what sounds to be the exact same symptoms. I could drive my car anywhere and the faint "flow-through" ventilation was the only air that would come out. The switch described, once replaced, made my climate control work as it should.

Dave
 

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Discussion Starter #7
Bro-Ham said:
Hi!

I had two postings recently about climate control issues. The first one dealt with what sounds to be the exact same symptoms. I could drive my car anywhere and the faint "flow-through" ventilation was the only air that would come out. The switch described, once replaced, made my climate control work as it should.

Dave
Ok, tonight the same thing was happening, so I played with the fan switch and moved it all the way over to Defrost and the blower on the windshield came on, then from there I was able to turn on the blower fans Hi Lo and Auto. It would not work going directly from off to Lo/Hi position, but move it all the way over to Def and then back and it was fine. Perhaps the contacts are worn?
 

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1979 Sedan deVille d'Elegance
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Hi,

My fan did seem to work sometimes and mostly in defrost. I don't know about the connections although Ape Man always suggests we check them for melting!

Good luck!

Dave
 

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1970 Sedan deVille hardtop
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IIRC, the fan will always come on in defrost. I suppose they assume you'll mostly be using defrost when the engine is cold anyways.
Dunno why the fan kept running after that, but it could be worm or gummed up contacts.
I would check the engine temp switch as well. On my '70 it is passengers side towards the front of the cylinder head. Once the engine is up to temp, use a multimeter to test for continuity between that connector and the negative battery terminal. No circuit means the switch is bad.
 
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