Announcement

Collapse
No announcement yet.

No heat, random heat, w/ATC. ARG!

Collapse
X
Collapse
 
  • Page of 3
  • Filter
  • Time
  • Show
Clear All
new posts
Previous 1 2 3 template Next
    #1

    No heat, random heat, w/ATC. ARG!

    Hey everyone, I've got a heat problem that's driving me nuts. I've searched the boards for quite a while, and can't find another issue quite like mine. I have a '90 CV with ATC. Here's the symptoms: about 80% of the time, my car blows cold air only on full-fan speed no matter the heat or fan speed settings. Randomly the heat will kick on, at which time the speed control starts working again, or at least tries to. What I mean by that, is sometimes it's all over the place, slowing down, speeding up, etc. At times, I'll be driving along with the heat cranked, with nothing but cold air blasting through the vents, and I'll notice a very soft "click" sound, and then a very slight electrical drag/pull, then the heat comes on.

    It definitely seems like some sort of electrical/HVAC problem, and not so much a heater core problem. I could see some of these symptoms happening if it was only when I had "automatic" selected (like the interior temp sensor clogged, etc), but this stuff happens no matter where my settings are. I did replace my ATC speed control board a while ago--before doing that, the heat worked perfectly fine, but I just had the high-fan speed only. My current problem differs from that, in that now I have only full speed fan no matter where the speed slider is. Before I replaced the speed control board, as soon as I pulled the slider off of "high", it stopped completely. Again, currently, once the heat kicks on, the fan starts blowing at the speed the slider is at.

    I've read gadget73's climate control sticky, and perhaps he's addressed it, but I'm not sure. In the "Poor heat, no heat, or temperature wanders" section, he seems to describe my problems, but my car does this stuff when on the manual settings, not auto, so I'm stumped. Sorry if this post is unnecessary--I've definitely tried to find the answer before posting this...

    Any ideas?
    1990 LTD Crown Victoria LX. As stock as the day it was born.
    16" HPPs sitting in the garage. That's it for now...kids gotta eat.

    Tags: ATC, blower, heat, HVAC, no heat
    #2
    The auto position is just for fan. It has nothing to do with temperature.

    here's the thing that I recently learned about some of the 90s cars. At least on the 1991 with ATC, it has the electronic blend door servo like the aero has. I don't know if the 1990 has this, or the vacuum stuff that the older models got. Need to know because the fix is very different. If you open the glovebox, is there a gold can in there with a vacuum line or do you see a rectangular box tucked back on top of the air plenum box?

    http://www.grandmarq.net/vb/showthread.php?t=39929 is the innards of a 1991 dash. This pic here has a shot of the air plenum with the electronic blend door actuator that might be your issue:



    The BDA is the whitish box thing with the plug. If you don't have this, you'll see a round gold vacuum motor hanging off the side. Its very obviously different looking.
    86 Lincoln Town Car (Galactica).
    5.0 HO, CompCams XE258,Scorpion 1.72 roller rockers, 3.55 K code rear, tow package, BHPerformance ported E7 heads, Tmoss Explorer intake, 65mm throttle body, Hedman 1 5/8" headers, 2.5" dual exhaust, ASP underdrive pulley

    91 Lincoln Mark VII LSC grandpa spec white and cranberry

    1984 Lincoln Continental TurboDiesel - rolls coal

    Originally posted by phayzer5
    I drive a Lincoln. I can't be bothered to shift like the peasants and rabble rousers

    Comment

      #3
      Well, for some reason I can't see the pics (behind a firewall at work), but I'm 90% certain there is no gold can with a vacuum line. After reading your sticky, I've gone out twice, pulled the glove box down, and looked for such a thing, and can't find it. If it should be obviously right in front of my face, then my car definitely has the electrical version. Once I get home I'll look for the white box, and snap a pic or two if I need to. Either way, is this for sure my problem?
      1990 LTD Crown Victoria LX. As stock as the day it was born.
      16" HPPs sitting in the garage. That's it for now...kids gotta eat.

      Comment

        #4
        oh boy, probably the electronic bullshit then. when those fail, they range from hot to cold randomly as you describe. No fix for it short of replacing it, which involves mostly pulling the dash apart, same as a heater core job.
        86 Lincoln Town Car (Galactica).
        5.0 HO, CompCams XE258,Scorpion 1.72 roller rockers, 3.55 K code rear, tow package, BHPerformance ported E7 heads, Tmoss Explorer intake, 65mm throttle body, Hedman 1 5/8" headers, 2.5" dual exhaust, ASP underdrive pulley

        91 Lincoln Mark VII LSC grandpa spec white and cranberry

        1984 Lincoln Continental TurboDiesel - rolls coal

        Originally posted by phayzer5
        I drive a Lincoln. I can't be bothered to shift like the peasants and rabble rousers

        Comment

          #5
          oh shit. no. NO.
          1990 LTD Crown Victoria LX. As stock as the day it was born.
          16" HPPs sitting in the garage. That's it for now...kids gotta eat.

          Comment

            #6
            Thanks for the input in any case...
            1990 LTD Crown Victoria LX. As stock as the day it was born.
            16" HPPs sitting in the garage. That's it for now...kids gotta eat.

            Comment

              #7
              Just thinking about something: does this explain the correlation with the fan speed? Whenever the heat is not working, the fan only runs on high, regardless of where the slider is. When the heat works, the fan runs according to the slider. Would the electronic BDA have something to do with this too?

              So...as far as pulling this dash apart, what should I expect? 5, 6 hours? More? Should I do the heater core while I'm down there? 91Grandmarquis, got any pointers beyond anything in the linked thread above? Thanks guys.
              1990 LTD Crown Victoria LX. As stock as the day it was born.
              16" HPPs sitting in the garage. That's it for now...kids gotta eat.

              Comment

                #8
                maybe. The fan speed won't have anything to do with the temperature unless you have it switched to auto mode though. If its changing speed on you when the switch is set to something other than auto, its possibly a different problem. Maybe there is some other gremlin in the works causing both issues? Honestly I don't know the later style climate controls at all and I have no documentation on them.

                I'd plan a weekend if you've never done one. Its a good 5-6 hours though. I'd do the heater core. You have to pull the box off the firewall to get the BDA, and its only like 4 more screws to change the core. It would really suck to put it all back together and find that the freshly disturbed solder joint on the original heater core decided to leak and now you have to take it all apart again to replace it.
                86 Lincoln Town Car (Galactica).
                5.0 HO, CompCams XE258,Scorpion 1.72 roller rockers, 3.55 K code rear, tow package, BHPerformance ported E7 heads, Tmoss Explorer intake, 65mm throttle body, Hedman 1 5/8" headers, 2.5" dual exhaust, ASP underdrive pulley

                91 Lincoln Mark VII LSC grandpa spec white and cranberry

                1984 Lincoln Continental TurboDiesel - rolls coal

                Originally posted by phayzer5
                I drive a Lincoln. I can't be bothered to shift like the peasants and rabble rousers

                Comment

                  #9
                  The fan speed won't have anything to do with the temperature unless you have it switched to auto mode though.
                  Yeah, that's exactly what I've been thinking. It's almost like the thing is tweaking out and thinking it's in auto mode. When the heat works, the fan speed works. When it doesn't, the fan only runs on high.

                  I have a very basic, dumb question. Where is the blend door? I understand now the actuator is either a vacuum controlled device on the older cars, and electronic on mine and the aeros, but where is the door itself? Is this the same thing I can see when I drop my glove box and look at the HVAC? There's a door there that opens and closes when I turn the fan on or off that lets me see through to the blower fan when it's open.
                  1990 LTD Crown Victoria LX. As stock as the day it was born.
                  16" HPPs sitting in the garage. That's it for now...kids gotta eat.

                  Comment

                    #10
                    that's the vent/recirculation door. The blend door should be totally hidden in the duct work to the driver side of the heater core IIRC. look to the left of the stuff you can see. You might be able to make out the electronic door controller mounted on top of the ducts (you'll probably only be able to see one edge of the thing though).

                    though from your description, I'm thinking it may just be a buggered connector to the fan speed switch or the "blend door lever" aka the ATC brain mounted to the control panel itself. Definitely sounds like an electrical contact issue from your description. I'm leaning more towards the brain connector though.

                    Only two things are infinite, the universe and human stupidity, and I'm not sure about the former. -- Albert Einstein
                    rides: 93 Crown Vic LX (The Red Velvet Cake), 2000 Crown Vic base model (Sandy), 2003 Expedition (the vacation beast)

                    Originally posted by gadget73
                    ... and it should all work like magic and unicorns and stuff.

                    Originally posted by dmccaig
                    Overhead, some poor bastards are flying in airplanes.

                    Comment

                      #11
                      yeah, blend door lives inside the box, under the servo. On the vacuum controlled models, you could see the crank arm sticking out the top and a rod sticking through the bottom but thats it. Not sure what the electronic ones have, but its probably no more visible than that.

                      Agree on it sounding like something outside of the BDA. That shouldn't have any effect on fan speed. Maybe try a different climate control panel to see if anything changes if there are no obvious problems with the plugs?
                      86 Lincoln Town Car (Galactica).
                      5.0 HO, CompCams XE258,Scorpion 1.72 roller rockers, 3.55 K code rear, tow package, BHPerformance ported E7 heads, Tmoss Explorer intake, 65mm throttle body, Hedman 1 5/8" headers, 2.5" dual exhaust, ASP underdrive pulley

                      91 Lincoln Mark VII LSC grandpa spec white and cranberry

                      1984 Lincoln Continental TurboDiesel - rolls coal

                      Originally posted by phayzer5
                      I drive a Lincoln. I can't be bothered to shift like the peasants and rabble rousers

                      Comment

                        #12
                        Thanks for the information and suggestions guys. I'll start poking around and see what I find. It's gotta be quick, cuz it's getting colder in the mornings up here!
                        1990 LTD Crown Victoria LX. As stock as the day it was born.
                        16" HPPs sitting in the garage. That's it for now...kids gotta eat.

                        Comment

                          #13
                          I did replace the fan speed controller a while ago. And the connection to the pigtail is kinda iffy--I had to solder it all back together in a cramped space, with some heavy gauge wire. I had cut it before, trying to get the incorrect blower motor resistor to work with my system. I was ignorant at the time That could definitely explain the trippy fan speed. The correlation with the heat though, I don't know...
                          1990 LTD Crown Victoria LX. As stock as the day it was born.
                          16" HPPs sitting in the garage. That's it for now...kids gotta eat.

                          Comment

                            #14
                            which is why I think it may be the "brain" of the ATC that may be flaking out... or the connections to said brain.

                            Only two things are infinite, the universe and human stupidity, and I'm not sure about the former. -- Albert Einstein
                            rides: 93 Crown Vic LX (The Red Velvet Cake), 2000 Crown Vic base model (Sandy), 2003 Expedition (the vacation beast)

                            Originally posted by gadget73
                            ... and it should all work like magic and unicorns and stuff.

                            Originally posted by dmccaig
                            Overhead, some poor bastards are flying in airplanes.

                            Comment

                              #15
                              thanks slymer. So you said the brain is attached to the controls? Or are they one and the same (if I replace the dash controls, are they inside the controls?) I haven't had the dash apart myself if you can tell
                              1990 LTD Crown Victoria LX. As stock as the day it was born.
                              16" HPPs sitting in the garage. That's it for now...kids gotta eat.

                              Comment

                              Previous 1 2 3 template Next
                              Working...
                              X