Lack of Heat

Topic: Lack of Heat (Read 3176 times) previous topic - next topic

Reply #15 – December 21, 2009, 05:56:08 AM

Quote from: jcassity;303377

My 20th runs me out of the car, the white coug also does the same.

Dang. It sounds like many of us have the problem of not a lot of heat. Its probably something silly.

Lack of Heat

Reply #16 – December 21, 2009, 01:04:59 PM

This is my 84 with a manual system and not the electronic climate control system.

Before I removed my dash to paint the rusted metal frame, I had a problem with airflow directing to where it needed to be. I found the defroster actuator vacspooge hose had slipped off and now I have no issues with airflow and everything works properly.

If your problem is directing airflow between defroster and dash vents in a manual system, it seems there could be a failure with the vacuum actuator that moves the flap to direct airflow between them. Look for loose vacuum hose that slipped off the actuator first. Vacuum sucks in the diaphram in the actuators to move the flaps. Sometimes the diaphrams in the vacuum actuators fail and get a hole in them. There is also a vacuum hose junction behind the glovebox near the blower motor housing. Also check to make sure the vacuum hose distributor connection behind the HVAC controls is tight and has not slipped off.

I don't recall a separate actuator for floor vents. It may be there and I can't see it from this picture and it has been awhile since I did this work on the vehicle.

There is also an actuator for interior air recirculation which is behind the glovebox on the right side of the dash. When the A/C is on MAX setting, this opens the flap to recirculate cabin air and pulls more air through the vent system.

In the center of the upper dash behind and to the left of the two dash center vents is an actuator that controls air flow between the dash vents and defroster vents. When there is no vacspooge to this actuator, the dash vents are disabled and air only flows to the defroster vents.

Hot and cold air is simply directed by the mechanical cable flap centered behind the radio and HVAC controls if you have manual HVAC controls.

If there is an issue with temperature, I would simply check the manual cable first for a complete range in movement then proceed to assure the thermostat is operating properly and that the heater core and hoses not clogged.

Lack of Heat

Reply #17 – December 21, 2009, 01:50:20 PM

Quote from: jpc647;303153

For any of you, is there a setting where heat will plow out of the cutouts in the dash? When I put it on mix, i feel it should come out through those vents but it doesn't.

The "MIX" position that is situated between the "Floor" and "Defrost" positions on the slider control should split the air between the Floor and Windshield. "Vent" is outside air through the dash registers, A/C compressor off, but can be heated by running the Temp lever up.

Another thing to check if air flow is not what it should be, is debris (or the work of a mouse) in the blower cage (the piece with the fins that spins).

In the 70's, the big Fords had a "Hi-Lo" position between A/C and Heat (Floor) that split the air between the Dash and the Floor outlets. That was good for warming up those big cars in a hurry. The small arrow between the "Heat" and "Defrost" positions was the split between the Floor and Windshield (what is now called "MIX"). Hijack off

Lack of Heat

Reply #18 – December 21, 2009, 02:07:14 PM

A better picture with the dash frame removed....

Lack of Heat

Reply #19 – December 24, 2009, 11:58:37 AM

I did not know about the defrost vac actuator.

also, see note i made on the hvac connector

Lack of Heat

Reply #20 – December 24, 2009, 01:42:46 PM

I don't get the "max" position on the blower speed anymore. It started going out a few years ago, only switching to max when a wiggled the slider but now the top blower speed setting does nothing, ever. Since losing this, everything takes much longer to warm up and defrost.

Also my replacement Siemens blower is MUCH noisier than the stock one that I replaced when doing the heatercore. Airflow was no different between the two.

Lack of Heat

Reply #21 – December 24, 2009, 09:08:57 PM

Quote from: Seek;303841

I don't get the "max" position on the blower speed anymore. It started going out a few years ago, only switching to max when a wiggled the slider but now the top blower speed setting does nothing, ever. Since losing this, everything takes much longer to warm up and defrost.

Also my replacement Siemens blower is MUCH noisier than the stock one that I replaced when doing the heatercore. Airflow was no different between the two.

yours is a contact issue on the mechanical linkages themselves. Usually people ocmplain that the heater works on max only and we tell them to replace the thermal limiter with an engineered substitured (ie- 30awg wire at the least).

Lack of Heat

Reply #22 – December 24, 2009, 09:42:05 PM

I know what the problem is but haven't bothered to fix it until I stumble across some rotary controls. The stock manual HVAC is HUGE in depth and the tight vacuum hoses just make me want to skip over it until I swap it out.

Lack of Heat

Reply #23 – January 26, 2011, 08:35:49 AM

If any of you guys set your setup to vent, or to AC Norm, air comes out through the 4 vents in the dash bezel. Do you all notice a significant difference between the volume in the middle two vents and the volume of air being blown through the two on the outside edge? Wondering if its just the tbird sucky HVAC system or if there is a problem.

Lack of Heat

Reply #24 – January 26, 2011, 11:23:48 PM

the heat in my 87 sucks too the floor on the passager side gets more heat than the driverside and it sucks it takes mine along time to heat up too.. i just think it our cars way of saying move south were its warm so we dont have to use the heat haha

Lack of Heat

Reply #25 – January 27, 2011, 08:37:28 AM

Alright. Well at least I know it's not a problem. Maybe I can do something about it. Good to know it's "normal".

Lack of Heat

Reply #26 – January 27, 2011, 08:59:02 AM

May be a normal issue but definitely not normal.. my 79 cougar used to burn me out of the car but now its lucky to get warm at all... I really think that autozone gave me a waterpump that is reverse rotation due to the fact that the coolant doesn't get warm and does not circulate.

Lack of Heat

Reply #27 – January 27, 2011, 12:41:49 PM

Quote from: 88turbo;350975

May be a normal issue but definitely not normal.. my 79 cougar used to burn me out of the car but now its lucky to get warm at all... I really think that autozone gave me a waterpump that is reverse rotation due to the fact that the coolant doesn't get warm and does not circulate.

So its normal for these 83-88 cars to have sucky head, but not normal for automibles... I agree. My 1972 Oldsmobile would burn me out of the car too. But then again I only drive that car in summer. But I do start it during the winter and leaving the heater on for 15-20 minutes, the car is hot..

Lack of Heat

Reply #28 – January 27, 2011, 05:33:01 PM

Quote from: jpc647;350981

So its normal for these 83-88 cars to have sucky head...

I'm not even gonna go there:rollin:

What was said before, about MIX being a mix of FLOOR and DEFROST is correct. You would naturally think it means floor and dash but alas, it does not. Also, MAX AC opens up the cabin air filter underneath the PS of the dash and lets a lot more air flow through. Your AC compresser will kick on, but as long as your slider is set to warm you will not get AC charged air out of it. And, also stated before, VENT is the air from outside the car being blown in, through your dash vents. It doesn't just mean air from your vents.

Here are a few misc tips that might help you out. I noticed some of this when I pulled my HVAC box a few months ago.

1. Make sure all the seals between your ducts and outside feeds are the sealed. When I pulled mine out I noticed that there is a large foam seal between the dash and airbox that was not properly seated. It was folded over onto itself and the dash vents were tightened down onto it so it wasn't flowing correctly.

2. Make sure that the flexible ducts that feed your vents are properly connected. {EDIT: I said on both sides, but I just checked and afaik they're only on the DS, just above the pedals and to the right} there are flex hoses that "plug in" to the bigger ducts. Make sure they are plugged up.

3. Make sure all vacuum lines that feed the HVAC system from the main vac tree under the hood are connected and not broken/cracked. I had that problem a couple years ago, and as was stated before, all I got was default defroster setting.

4. And this is debatable, check the hose that feeds your heater core from the water pump, and see if the factory reducer is still in the hose. If you take that out, it will allow more water flow to your core, and more than likely, it will get warmer. But, be wary. Some people will tell you that if you take that reducer out you are far more likely to ruin/blow up your heater core. Other people will tell you it doesn't make a difference. I say do so at your own risk.

5. The DUH stuff. MAKE SURE your dash vents are set to open, not closed. Its easy to get the settings mixed up. Also, it might not hurt to pull your dash bezel off and make sure the vents are seated properly into the ducts, and that all the ducts are properly intact also.

Hope something there helps.

Also, I don't know how long your letting it run for, but sometimes these cars take a hella long time to warm up. Mine takes about 10-15min for the tstat to open up, depending on outside temperature. And even after that, you have to wait for the warm air to fully circulate in the car.