1990 Eldorado heater n/w
Cadillac
 

Cadillac Forums | Help Us Help You | Advertise | Cadillac Parts | Cadillac News | Cadillac Classifieds / (Old System)

Cadillac Technical Archive | Cadillac Dealers | Cadillac Reviews | Cadillac Dealer Reviews | Cadillac Vendors

CadillacForums.com is the premier Cadillac Forum on the internet. Registered Users do not see the above ads.
+ Reply to Thread
Page 1 of 2 1 2 LastLast
Results 1 to 15 of 30
Cadillac Seville / Cadillac Eldorado Forum Discussion, 1990 Eldorado heater n/w in Past Cadillac Vehicle Discussion; My 1990 Eldorado heater is not working. There is no wetness nor smell, so I don't think it's the heater ...
  1. #1
    vegasdano is offline Cadillac Owners Member
    Automobile(s): 1990 Eldorado
    Join Date
    Dec 2009
    Posts
    11

    1990 Eldorado heater n/w

    My 1990 Eldorado heater is not working. There is no wetness nor smell, so I don't think it's the heater core. Is there a heater control valve, and if so, where is ti located. Thank you

  2. Remove Advertisements
    CadillacForums.com
    Advertisements
     

  3. #2
    Ranger's Avatar
    Ranger is offline Cadillac Owners Member
    Automobile(s): White Diamond '03 DHS (with DTS floor shift)
    Join Date
    Jun 2004
    Location
    Woodstock Ill.
    Age
    66
    Posts
    72,351

    Re: 1990 Eldorado heater n/w

    4.9? Has any work been done to the cooling system?

  4. #3
    vegasdano is offline Cadillac Owners Member
    Automobile(s): 1990 Eldorado
    Join Date
    Dec 2009
    Posts
    11

    Re: 1990 Eldorado heater n/w

    The thermostat was replaced this summer

  5. #4
    VEGASELDO91 is offline Cadillac Owners Fanatic
    Automobile(s): 1991 ELDORADO (R.I.P.); 1995 Sedan Deville
    Join Date
    Nov 2009
    Posts
    324

    Re: 1990 Eldorado heater n/w

    Not to thread jack but I noticed my heater isn't working either! I was told that the AC unit has been converted to R-134 and although it blows cold air the DIC says Refridgerant low/ AC compressor off. Don't know if this affected the heater or not.

  6. #5
    drewsdeville's Avatar
    drewsdeville is offline Cadillac Owners Master
    Automobile(s): none
    Join Date
    Oct 2004
    Location
    WI
    Posts
    5,280

    Re: 1990 Eldorado heater n/w

    You may have some problems behind the dash. Temp output is controlled by some linkage and doors behind the dash. Most of it is visible if you just take out the glove box...4-5 screws. When you switch from a warm to cool temp, you should see the linkage moving. If it's not moving, diagnose further.

    There is no real heater control valve on the '90, just a restrictor to the heater core on the heater hoses that can't "fail" besides leaking externally.

  7. #6
    SSG
    SSG is offline Cadillac Owners Member
    Automobile(s): NONE
    Join Date
    Nov 2009
    Posts
    26

    Re: 1990 Eldorado heater n/w

    Go into your on board diagnostics and check your coolant temperature. It should be over 195F or 85C. Just press the off and warmer buttons at the same time and hold them for about 5 seconds and you will go into diagnostic mode.

  8. #7
    Ranger's Avatar
    Ranger is offline Cadillac Owners Member
    Automobile(s): White Diamond '03 DHS (with DTS floor shift)
    Join Date
    Jun 2004
    Location
    Woodstock Ill.
    Age
    66
    Posts
    72,351

    Re: 1990 Eldorado heater n/w

    Sounds like an air mix actuator. Follow Drews advice.

  9. #8
    Sevillian273's Avatar
    Sevillian273 is offline Cadillac Owners Connoisseur
    Automobile(s): 69 Thunderbird | 90 Seville | 89 Marquis | 72 Torino
    Join Date
    Oct 2008
    Location
    Palm Bay, FL
    Posts
    2,022

    Re: 1990 Eldorado heater n/w

    Check for code B440. The part is called the 'ECC Programmer'. Good luck finding a new one.... You can un-clip the bar that moves the air mix door and slide it manually to the heat position just to get you by until you can fix it.

    ECC is in green:

  10. #9
    vegasdano is offline Cadillac Owners Member
    Automobile(s): 1990 Eldorado
    Join Date
    Dec 2009
    Posts
    11

    Re: 1990 Eldorado heater n/w

    Thank you for your responses, especially the photo. Will let you know what I find out.

  11. #10
    VEGASELDO91 is offline Cadillac Owners Fanatic
    Automobile(s): 1991 ELDORADO (R.I.P.); 1995 Sedan Deville
    Join Date
    Nov 2009
    Posts
    324

    Re: 1990 Eldorado heater n/w

    I myself do not have the B 440 code but I do have the B 335 code in the history. Could this code affect the heating problem? It is becoming more than just a comfort problem now; my defroster isn't working and it is making it hard to see at times! Thanks!!

  12. #11
    VEGASELDO91 is offline Cadillac Owners Fanatic
    Automobile(s): 1991 ELDORADO (R.I.P.); 1995 Sedan Deville
    Join Date
    Nov 2009
    Posts
    324

    Re: 1990 Eldorado heater n/w

    I pulled the glove box to check the linkage arm (just to be sure); it seems to be working properly. Where should I look to next? Thanks!

  13. #12
    drewsdeville's Avatar
    drewsdeville is offline Cadillac Owners Master
    Automobile(s): none
    Join Date
    Oct 2004
    Location
    WI
    Posts
    5,280

    Re: 1990 Eldorado heater n/w

    The since the code is in history, and you verified the Climate Control is working correctly, I woudn't worry about the B335. What's th engine temp in the DIC when you are trying to use the heat?

    If the temp is normal operating temp, I'd have to suggest the heater core is plugged or disconnected. That or you have air in the system due to combustion leakage through headgaskets... Do you ever have to add coolant?

  14. #13
    VEGASELDO91 is offline Cadillac Owners Fanatic
    Automobile(s): 1991 ELDORADO (R.I.P.); 1995 Sedan Deville
    Join Date
    Nov 2009
    Posts
    324

    Re: 1990 Eldorado heater n/w

    Quote Originally Posted by drewsdeville View Post
    The since the code is in history, and you verified the Climate Control is working correctly, I woudn't worry about the B335. What's th engine temp in the DIC when you are trying to use the heat?

    If the temp is normal operating temp, I'd have to suggest the heater core is plugged or disconnected. That or you have air in the system due to combustion leakage through headgaskets... Do you ever have to add coolant?

    Thank you for the tips and info.; I found the problem! It turns out one of the hoses that connects to the heater core was totally disconnected and the other was rerouted and connected to the T connecter. I had to face the possibility that the heater core was leaking and the previous owner disconnected it. I reattached the hoses to their rightful places (thanks to ALL-DATA) and started the car; there was a little seepage from one of the hoses and as the car got hotter it started to actually spray! There was no fluid leaking into the cabin and it felt like it was starting to warm up!!

    I cut the hose past the area that was leaking and reattached it, I let the car run for around 20 min. with temp set at 90 and on high. It took awhile for it to heat up the cabin but there was no leaks noted, as I drove around the parking lot of my job it started to get hotter faster. So hopefully the only problem was the leaking hose (already ordered new ones), I will drive it home and let it sit overnight and check for moisture in the passenger side tomorrow.
    Thank you again for your helpful info; and I hope Vegasdano finds his problem too!

    P.S. Sorry for the novel post!!

  15. #14
    Ranger's Avatar
    Ranger is offline Cadillac Owners Member
    Automobile(s): White Diamond '03 DHS (with DTS floor shift)
    Join Date
    Jun 2004
    Location
    Woodstock Ill.
    Age
    66
    Posts
    72,351

    Re: 1990 Eldorado heater n/w

    The ONLY reason to bypass the heater core is because it has a leak. If it is small, it may not drip, but it will fog the windows so keep an eye out for that.

  16. #15
    VEGASELDO91 is offline Cadillac Owners Fanatic
    Automobile(s): 1991 ELDORADO (R.I.P.); 1995 Sedan Deville
    Join Date
    Nov 2009
    Posts
    324

    Re: 1990 Eldorado heater n/w

    Quote Originally Posted by Ranger View Post
    The ONLY reason to bypass the heater core is because it has a leak. If it is small, it may not drip, but it will fog the windows so keep an eye out for that.
    I will definately keep an eye out; thank you for the tip! Just so I understand; will it only fog up the windows when I am using the heater or will it still do it when the heater is off too?

Quick Reply Quick Reply

Register Now

Please enter the name by which you would like to log-in and be known on this site.
If you do not want to register, fill this field only and the name will be used as user name for your post.

Please enter a password for your user account. Note that passwords are case-sensitive.

Please enter a valid email address for yourself.

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Bookmarks

Cadillac Posting Rules

  • You may post new threads
  • You may post replies
  • You may not post attachments
  • You may not edit your posts
Read about Lincoln | Buick | Kia Forte Forum
Need products for your Cadillac? Check out your options at the links below:

custom floor mats | Cadillac Chrome and Black Chrome Wheels | window tinting