1984 Cadillac NO HEAT, blower working

Hi "Sands" ??/

I use to have a problem with the "heat" in my older GM vehicle, and sounds like to me YOURS is a "Mixing" problem. Kind of hard for me to explain, but all the controls for your heat are vacuum operated and little doors open and close to mix hot and cool air (Blend) into the vehicle. To make it simple, I would start by grabbing a flashlight and looking under dash and around firewall for any vacuum hoses cracked or slipped off their units. After that you got to go into the controls for the vacuums, but start with the obvious first. If your heater hoses are 'hot", its definitely a control problem. Take a good look under dash and even try to move by hand any solenoid you can find to eliminate the problem!

hope this helps!

Sounds like a vacuum line is plugged. This is the one that controls the lever that allows warm coolant into the heater core? Just guessing. Is this computer controlled with the climate system,............experts please!

Thanks! ...but which solenoids? Where? Around the AC module?

How can i check a vacuum line? (That is plugged or not)

Some of your posts are easy to associate with a previous post, but when you don't include the text from the post you're replying to it often becomes impossible to follow the train of thought. Context is everything. Usenet is a written forum and it occurs over a protracted period of time, not real time. Things get mixed up. If you want help, please do the service to those willing to offer help as they can, and provide intelligible conversation trails. Not everything, just relevant information.

Why is it that google users and web-tv users are the worst at this?

Never mind... rhetorical question.

When the car is warm and the heat is on, are both hoses going to the heater core hot?

Yes! Both hoses are hot.

Yes! Both hoses are hot.

The hoses hot but the blower blows cool air. No air from side or other intakes, just from the front intake bottom of the windshield...Why?

Because they don't know how to copy and paste!!

---MIKE---

Since both hoses are hot, it would indicate that hot water from the engine IS passing through your heater core. Good.

Your blower is apparently blowing air through the maze of the heater unit but the airstream is not going past the heater core. That means that one or more of the doors or baffles inside the unit is not in the proper position. These are usually controlled by vacuum actuators. You should have a vacuum reservoir or cannister in the engine compartment somewhere. Be sure it is not cracked or leaking. Be sure the hoses are on it properly and are not kinked or cracked anywhere.

If you have full vacuum to the actuators, and the baffles/doors are not opening properly, then they may be mechanically stuck and you will have to free them by hand.

Last, the controls for the heating unit are sometimes mechanical and sometimes electronic. If mechanical, you may have a broken wire, binding wire, a wire that has come undone, etc.. (These can be a pain in the ass to work on). If electronic, the entire control module may be defective.

Like others have said you need to check for vacume leaks and the baffle doors wich controle the air and heat mix. If all are good then i would look at the controle module. Its not that hard. Can be a pain to do but its not hard. That is why you dont have heat geting inside the car. But the hoses are hot.