General Tech Good at troubleshooting? Have a non specific issue? Discuss general tech topics here.
Sponsored by:
Sponsored by:

1984 Cadillac Deville - heater not working

Thread Tools
 
Search this Thread
 
  #1  
Old 02-25-2008, 02:26 PM
fishnmachine's Avatar
Thread Starter
Join Date: Jun 2007
Location:
Posts: 9
Default 1984 Cadillac Deville - heater not working

I don't drive the car in the winter, but I would like to fix this, I have no heat, it just blows cold air, the lined into the core are cold, coolant is full, upper rad hose is warm, but I don't feel a big surge if I pinch it, can a bad water pump cause this? is there anything else I can look at?









==============
MOD edit
Title


 
  #2  
Old 02-25-2008, 09:17 PM
slowroll's Avatar
Tech Certified Members
Join Date: Oct 2007
Location: in the mitten
Posts: 3,160
Default RE: 84 heater not working

Possibly thermostat stuck open, hose from engine to core and upper radiator should be hot to the touch...ie 200 degrees
 
  #3  
Old 02-27-2008, 05:35 PM
carnut's Avatar
Tech Certified Members
Join Date: Feb 2008
Posts: 463
Default RE: 84 heater not working

Replace thermostat. Get one rated at 195 degrees. Once replaced, report back. also list type of Cad in your profile signature. Eldo, Seville, etc.
 
  #4  
Old 04-07-2008, 10:18 AM
fishnmachine's Avatar
Thread Starter
Join Date: Jun 2007
Location:
Posts: 9
Default RE: 84 heater not working

replaced thermostat, no change, 84 deville is what it is.
 
  #5  
Old 04-08-2008, 02:06 PM
carnut's Avatar
Tech Certified Members
Join Date: Feb 2008
Posts: 463
Default RE: 84 heater not working

Remove the glove box liner. You will see a threaded metal rod attached to a white plastic arm. As temperature changes and the climate system is on, the arm will move the rod allowing heated air into the cabin. To verify, start car, in "auto" mode, change the display from 60 to 90 degrees. You will see the rod move away towards the firewall at 60 degrees and towards you at 90 degrees. This arm should move slowly and smoothly and take a couple on min. to fully react. If the rod does not move or is jerky, the climate control module needs replaced. Thats the large black box the plastic arm comes out of. The rod simply moves the blend door in the dash much like sliding the lever in a manual heat/A/C system. Verify the rod movement and report back.
 
  #6  
Old 04-08-2008, 02:49 PM
Stealth's Avatar
Super Moderator
Join Date: Feb 2007
Posts: 3,945
Default 1984 Cadillac Deville - heater not working

ORIGINAL: fishnmachine

I don't drive the car in the winter, but I would like to fix this, I have no heat, it just blows cold air, the lined into the core are cold, coolant is full, upper rad hose is warm, but I don't feel a big surge if I pinch it, can a bad water pump cause this? is there anything else I can look at?
If the water pump was bad, the car would overheat. You make no mention of overheating.

May I assume that you meant "THE lines into the heater core are cold" ? ? ?

When was the coolant changed? if longer than two years, I suggest you jump on that ASAP.
Have you checked the arm and control module that carnut suggested?
Have you back flushed the heater core?
Has the heater ever worked since you bought the car? (is the core connected?)
Does the A/C work, meaning it blows ice cold air?



.
 
  #7  
Old 04-11-2008, 09:44 AM
fishnmachine's Avatar
Thread Starter
Join Date: Jun 2007
Location:
Posts: 9
Default RE: 1984 Cadillac Deville - heater not working

the car has not overheated

yes the lines into the core

coolant is new, not fushed though

heater has never worked

AC works fine

I have owned the car for about a year but have only put 300 miles on it. I will try what carnut said and let you know. Thanks
 
  #8  
Old 05-08-2008, 02:13 PM
stomper's Avatar
Tech Certified Members
Join Date: Jun 2007
Posts: 2,701
Default RE: 1984 Cadillac Deville - heater not working

ORIGINAL: fishnmachine

the car has not overheated

yes the lines into the core

coolant is new, not fushed though

heater has never worked

AC works fine

I have owned the car for about a year but have only put 300 miles on it. I will try what carnut said and let you know. Thanks

Status ?


 
  #9  
Old 05-08-2008, 03:26 PM
carnut's Avatar
Tech Certified Members
Join Date: Feb 2008
Posts: 463
Default RE: 1984 Cadillac Deville - heater not working

We dont his age, so hopefully he's still alive? Maybe he froze??
 
  #10  
Old 05-08-2008, 03:51 PM
stomper's Avatar
Tech Certified Members
Join Date: Jun 2007
Posts: 2,701
Default RE: 1984 Cadillac Deville - heater not working

Or went fishing?



 


Quick Reply: 1984 Cadillac Deville - heater not working



All times are GMT -5. The time now is 07:03 PM.