Mechanics

CADILLACE HEAT ISN'T WORKING

2002 Cadillac Deville

The heat in my 2002 Cadillac Deville only sometimes works. I drove 20 minutes with no heat. Then suddenly it started working again. Any thoughts on what might be wrong?
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Dlgobeavs
February 25, 2011.



U have to ck. The heater control valve on hoses that run to a/c case. If valved doesnt open youll have no heat. Turn the heat on watch the valve u should see it open when the car warms up if no you can manually open it by hand. Hold it open and have some1 ck. For heat. If so replace the valve. Its vac. Opered the diafram is bad it is cheap repair good luck

Cadieman
Feb 25, 2011.
Is it the fan that stops working or it just has no hot air? If the fan stops working you might have a faulty relay that heats up if the air goes from hot to cold then the Flap under your dash is flipping back to cold side. Either way its electrical. I would look up where the relays are.

Tiny
Viperkorn
Feb 25, 2011.
The fan is working fine. The issue is with the air temperature.
Viperkorn- Any idea where I might find the relay location? Cadieman- with that new bit of info I just provide does that change your answer at all?

Much thanks!

Tiny
Dlgobeavs
Feb 25, 2011.
U need flow through the core to have heat hence its the valve

Cadieman
Feb 25, 2011.
Cadieman: Where is this valve located? What is the official name of the valve so I could google it?

Tiny
Dlgobeavs
Feb 25, 2011.
Its on the heater hoses that go into a/c case heater control valve

Cadieman
Feb 25, 2011.
There is no heater control valve on your Sedan, it is all done with blend doors in the HVAC case. Does the heater seem to be warmer as engine speed is increased, it may still be a flow problem, may also be result of low liquid level in the cooling system.

Factoryjack
Mar 4, 2011.