My wife's Delta 88 continuously blows cold air no matter what the heat setting is. I've gone through the flow chart in the service manual and pretty much determined that the problem is the temperature control door. According to the chart moving this from cold to hot I should hear the door open and close, which I don't. I've reverse flushed the heater core anyway to be safe and it flows nicely. According to the manual there is no adjusting the cable for the temperature door, it has to be replaced. Has anyone experience with doing this?

Thanks
Chris

 

It is almost certainly a broken heater blend door bellcrank, a common failure in the 1977-1990 B-body cars. See this post:

https://classicoldsmobile.com/forums/134760-post11.html

 

Thanks Joe, I removed the glove box and found the temp control cable. When moving the temp control slider the top part of the vertical piece moves but the bottom doesn't. I can't seem to locate the piece you mentioned in the link. I've attached a picture of what I can see. Possibly you can help me locate where the broken piece is at.

Thanks for the help
Chris

 

yeah, is that the cable with the red colored retainer clip on it? not to difficult, the hardest part is not destroying all that vintage plastic trim and ductwork that needs to be removed. the cable part is straight forward once you get access to the control. it's self explanatory once you see it.

 

I'll have to take another look this weekend if the weather coorporates. I don't remember any red colored retainer clip but then that was a month ago. I'll get back to you on this.

Thanks
Chris

 

thanks, i hope i'm talkin about the right one your tryin to fix. i replaced it in my cutlass(76). was pretty straight forward.

 

I'm having the same issues. I use to be able to see the door open and close before when the glove box was removed. A few days ago the heat completely went away so today i removed the glove box and found the vacuum hose that goes to the housing right under those cables had came off. I put it back on but nothing changed. The door doesn't move at all. I believe i have a vacuum leak somewhere because the air comes out defrost and floor no matter what setting i put it on. Doesn't switch anymore. I use to get in the car after not driving it for a while and you could hear something slam shut. I think it was that door but now nothing is going on. Super cold temp coming out. I already replaced the heater core and today i flushed it to make sure. Heater control valve went bad so i just removed it and put the hose directly on so it's always flowing to the heater core. But years ago when i changed the heater core the heat was never the same. I hate this whole vacuum system. It's ridiculously a pain in the rear. Some years ago i inspected the vacuum hoses coming off the control Panel in the car, someone poked holes in all of them thinking they were electrical wires. I used super glue in the holes and then wrapped them in electrical tape which sort of fixed it. i could then hear it cycling through defrost and floor settings. you could hear the vacuum actually working which before when i first got the car nothing worked at all. Any suggestions on why the heat went away completely a few days ago. I was kinda happy with the heat before, it came out warm, enough to defrost windows but now it's ridiculously cold.