Heat on 84 Caddy not working

[NJDooWopper]

Hello,

The heater on my 84 Caddy isnt working, even when cranked up to 90 on the thermostat. I dont know if its a vaccume hose or what, but any help is greatly appreciated!

 

[JoshMcMadMac]

It could be a bad heater core. I would check that first.

 

[Katshot]

What's it not doing? Is the fan running? Is there air blowing out the vents? Is the air coming out just not hot? Need a little more info.

 

[Pepsi2185]

Im gonna second katshot. From what you described, you have a lot of testing ahead of you. Is the controller built into the display or is it separate from the display?