The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post

**TBONE1964** · 08-14-2013, 08:45 AM

A couple of things come time mind:

Is the coolant level OK?

How long do you let it run to check the heat? If the t-stat is stuck open it will take the engine a lot longer to get to operating temp. Also how is the engine temp? Is it at least 180 degrees?

You should have a vacuum operated heater control valve if your truck has AC. Is there a vacuum source hooked to it and does it work? Have you felt the heater hoses, in and out? Are they both the same temp or is one hot and one cool? If you are unsure about the heater control valve, remove it and run a straight hose from the heater core to the engine and see what happens. If you have one hot and one cool in this case, the heater core may be plugged

Is the cable for the heat door moving the heat door in it's complete motion? Sometimes the cables can get stretched and not move the heat door properly.

Make sure the above mentioned items are good and then we can see what needs to happen.

08-14-2013, 08:45 AM	#2
TBONE1964 Cluster King Join Date: Nov 2012 Location: Junction City, OR Posts: 5,263	Re: Why dont I have heat? A couple of things come time mind: Is the coolant level OK? How long do you let it run to check the heat? If the t-stat is stuck open it will take the engine a lot longer to get to operating temp. Also how is the engine temp? Is it at least 180 degrees? You should have a vacuum operated heater control valve if your truck has AC. Is there a vacuum source hooked to it and does it work? Have you felt the heater hoses, in and out? Are they both the same temp or is one hot and one cool? If you are unsure about the heater control valve, remove it and run a straight hose from the heater core to the engine and see what happens. If you have one hot and one cool in this case, the heater core may be plugged Is the cable for the heat door moving the heat door in it's complete motion? Sometimes the cables can get stretched and not move the heat door properly. Make sure the above mentioned items are good and then we can see what needs to happen.