Fox T-Bird/Cougar Forums

Technical => Misc Tech => Topic started by: deathbypsi on September 27, 2016, 10:49:12 PM

Title: No heat question
Post by: deathbypsi on September 27, 2016, 10:49:12 PM
So my freshly built 83 TC is on the road and turned out great. Getting the last few bugs worked out now and my biggest one is I have no heat.

 My motor has plenty of hot coolant flowing through the heater hoses. My MicroSquirt shows 190* engine temps. The heater core was said to be brand new before I got the car. All of my HVAC controls seem to work as they should but I need to pull the glovebox back out and try to see if the door in the box for the fresh air at the cowl is stuck open.

Anybody know what or where to look for the fresh air door ?
Title: No heat question
Post by: softtouch on September 28, 2016, 04:52:11 PM
ATC or Manual?
Is the air coming out somewhere, floor or defrost?
Title: No heat question
Post by: deathbypsi on September 28, 2016, 07:04:23 PM
Manual

All HVAC functions work like they should, just no heat in the air being blown out.
Title: No heat question
Post by: TheFoeYouKnow on September 28, 2016, 07:25:36 PM
Did you purge the cooling system properly?  An air-locked cooling system usually stalls coolant flow through the heater core.  Try loosening the clamp at the firewall and using a bent pick to let air out between the hose and the nipple.
Title: No heat question
Post by: TurboCoupe50 on September 28, 2016, 08:30:06 PM
With both hoses hot, you're gonna have to figure out why the air isn't routing through the core...

I think somewhere around here are links to various year EVTMs that should picture the door operation inside the plenum..
Title: No heat question
Post by: CougarGal on September 30, 2016, 11:35:47 AM
Following this thread because I'm having the same issue in my '86 XR-7.    New thermostat, radiator, hoses and heater core but still not heat :(
Title: No heat question
Post by: softtouch on September 30, 2016, 02:27:34 PM
The temperature control operates the temperature blend door mechanically with a cable.
If the blend door stays in the cold position, the air will bypass the heater core.
I see in a shop manual picture that the door is spring loaded. I can't tell which way it will go if the cable is disconnected or broke.

After studying the pics, I have convinced myself the door is spring loaded to go to the cold side.
Title: No heat question
Post by: softtouch on September 30, 2016, 03:38:29 PM
Pics:
Title: No heat question
Post by: deathbypsi on October 01, 2016, 11:38:14 AM
HA! You nailed it.  That self adjusting clip in view A I found under the floor mat and didnt know what it was for! Now to go find where I put it and reinstall it. Thank you!
Title: No heat question
Post by: softtouch on October 01, 2016, 11:20:59 PM
You're welcome.
Title: No heat question
Post by: AlabamaWildman on November 28, 2016, 04:52:27 PM
"... loosening the clamp at the firewall and using a bent pick to let air out ..."

May I ask for a little clarification on how to actually do this, please ??
.. never tried something like that.

Thanks !
Title: No heat question
Post by: TurboCoupe50 on November 29, 2016, 08:43:45 AM
Quote from: AlabamaWildman;458286
"... loosening the clamp at the firewall and using a bent pick to let air out ..."

May I ask for a little clarification on how to actually do this, please ??
.. never tried something like that.

Thanks !
If coolant is not circulating through core, either it's blocked, there is a collapsed hose or water pump isn't operating(seen ones with rotted impellers move coolant through radiator but not have enough flow to push coolant through heater hoses)... With properly operating components, burping a heater core should not be necessary...
Title: No heat question
Post by: CougarGal on November 29, 2016, 11:21:43 AM
Okay, next question:  New Parts:  Radiator, water pump, thermostat, upper and lower radiator hoses - STILL NO heat.  When moving the temperature selector from cold to hot, I am not hearing any sort of 'flap' moving under the dash.  Is there an easy way to move this thing manually without taking the whole dash apart?  I realize that moving it manually will mean that my heat stays on but, at this point, I'm good with that for a few months :)
Title: No heat question
Post by: softtouch on November 29, 2016, 04:25:22 PM
Quote from: CougarGal;458294
Okay, next question:  New Parts:  Radiator, water pump, thermostat, upper and lower radiator hoses - STILL NO heat.  When moving the temperature selector from cold to hot, I am not hearing any sort of 'flap' moving under the dash.  Is there an easy way to move this thing manually without taking the whole dash apart?  I realize that moving it manually will mean that my heat stays on but, at this point, I'm good with that for a few months :)

Heater hoses get warm?
Manual or Automatic Temperature Control (ATC) ?
Title: No heat question
Post by: CougarGal on November 29, 2016, 04:26:52 PM
Quote from: softtouch;458301
Heater hoses get warm?
Manual or ATC?

Both heater hoses get HOT and it's the manual slide type switch.
Title: No heat question
Post by: softtouch on November 29, 2016, 04:50:21 PM
Should not have to remove the dash but will have to stand on your head.
The "crank handle" on the blend door shaft operates the blend door.
It is spring loaded to go to the cold setting. The air bypasses the heater core.
The "crank handle" should be plugged into a clip attached to a cable that the temp control operates.
More pics in post #8 of this thread.
Title: No heat question
Post by: AlabamaWildman on November 29, 2016, 05:03:41 PM
Quote from: TurboCoupe50;458292
... With properly operating components, burping a heater core should not be necessary...

New Radiator .. New Water Pump.
Both Heaters Hoses are HOT @ operating Temps.

--- So, Problem Must Be Behind the Dashboard


THANKS !! !!
Title: No heat question
Post by: CougarGal on November 29, 2016, 07:16:16 PM
Quote from: softtouch;458303
Should not have to remove the dash but will have to stand on your head.
The "crank handle" on the blend door shaft operates the blend door.
It is spring loaded to go to the cold setting. The air bypasses the heater core.
The "crank handle" should be plugged into a clip attached to a cable that the temp control operates.
More pics in post #8 of this thread.

Thanks!  Guess one of will get to play contortionist this weekend!  Wish us luck!
Title: No heat question
Post by: softtouch on November 29, 2016, 07:39:09 PM
Take out the 4 screws and pull the temp control out of the dash to get to the top end of the cable.
See the 3rd pic in post #8
Title: No heat question
Post by: CougarGal on November 30, 2016, 09:15:26 AM
Quote from: softtouch;458309
Take out the 4 screws and pull the temp control out of the dash to get to the top end of the cable.
See the 3rd pic in post #8

Got it!!!
Title: No heat question
Post by: AlabamaWildman on November 30, 2016, 05:33:40 PM
Quote from: softtouch;458309
Take out the 4 screws and pull the temp control out of the dash to get to the top end of the cable.
See the 3rd pic in post #8


Did that, this afternoon, and no new results
Title: No heat question
Post by: Aerocoupe on December 02, 2016, 10:20:10 AM
Just a quick note, when replacing the thermostat I drill a 1/8" hole at the top of the housing so that air can continuously burp out of the system.  Been doing this for years on my Fords and never have a problem with air in the coolant system.  When both of the heater core hoses are hot this means coolant is circulating through the heater core and the issue is inside the cabin of the car.
Title: No heat question
Post by: CougarGal on December 02, 2016, 02:26:52 PM
Quote from: Aerocoupe;458331
Just a quick note, when replacing the thermostat I drill a 1/8" hole at the top of the housing so that air can continuously burp out of the system.  Been doing this for years on my Fords and never have a problem with air in the coolant system.  When both of the heater core hoses are hot this means coolant is circulating through the heater core and the issue is inside the cabin of the car.

Thanks for the advice!!!  We're thinking now that it's got to pretty much be something under the dash, either mechanical or a vacuum line.  Husband is working on getting up his nerve to pull the dash apart again (last time was to replace the heater core and he did NOT have a good time :(
Title: No heat question
Post by: AlabamaWildman on December 02, 2016, 05:51:13 PM
Quote from: Aerocoupe;458331
"... I drill a 1/8" hole at the top of the housing so that air can continuously burp out of the system ..."

... and No Problem with Any Amount of Coolant Leaking ??

.. .. Interesting
Title: No heat question
Post by: softtouch on December 02, 2016, 07:33:04 PM
Quote from: AlabamaWildman;458316
Did that, this afternoon, and no new results
Did you see the cable attached to the temperature control lever?
Title: No heat question
Post by: AlabamaWildman on December 02, 2016, 11:20:30 PM
Quote from: softtouch;458336
Did you see the cable attached to the temperature control lever?

Yes !
... moved the "Adjustment Slider" to the location shown on the Drawings.
The Door can be heard as it closes but Very Little Change in the Air Flow
Title: No heat question
Post by: softtouch on December 03, 2016, 01:12:23 AM
Quote from: AlabamaWildman;458338
Yes !
... moved the "Adjustment Slider" to the location shown on the Drawings.
The Door can be heard as it closes but Very Little Change in the Air Flow
The location in the drawing is "pre-set adjustment".
The final "self-adjusting" is the "rapid movement of the temperature control lever to the extreme right of the slot (warm) in the control assembly"
This should slid the clip to where it needs to be to allow the door to move to the full warm position.

Note that the air goes through the A/C evaporator core before it gets to the heater core. If for some reason the A/C compressor is running that will cancel out the heat.
Title: No heat question
Post by: jcassity on December 03, 2016, 10:57:30 AM
note on drilling a tiny hole in your Tstat as a failsafe and helping get rid of air..........

make the hole a  tad smaller than 1/8''

in very very very cool temps, you may not make enough heat at the heater core like was my case last winter.

in order to make heat i had to cover 50% of the front of the rad with cardboard to help a little bit.

sorry for the hijack.

in the engine bay there is a tinty iddy biddy black vac line that comes from the vac tree and travels across the fire wall and pops into the cabin on the passanger side.
this is the main vac line source for vac controlled pieces parts in the dash.

make sure that tiny black vac line is connected & not broke or the tree iteself is not cracked.
without this vac source, the interior hvac controlls will not work right,, included in the inspection would be the check valve softtouch illustrates on the EVTM.. this check valve is in the engine bay just prior to where the vac line penetrates the firewall.
Title: No heat question
Post by: AlabamaWildman on December 03, 2016, 12:43:45 PM
GREAT Info ... Thanks ! !!

Hoping to be able to get that  Dash Loose
(and not having it Shatter due to the Cold Temps !)
Title: No heat question
Post by: AlabamaWildman on December 03, 2016, 01:08:22 PM
Question:

Does anyone know about the possibility of "Looking Thru" the side of that HVAC Duct ?
... using an Inspection Camera (ala Harbor Freight (http://"http://www.harborfreight.com/digital-inspection-camera-61839.html")) and Drilling a Hole only Large enough to allow the camera access ??
without the need of removing the Dashboard ??
Title: No heat question
Post by: jcassity on December 03, 2016, 02:01:48 PM
Quote from: AlabamaWildman;458348
Question:

Does anyone know about the possibility of "Looking Thru" the side of that HVAC Duct ?
... using an Inspection Camera (ala Harbor Freight (http://"http://www.harborfreight.com/digital-inspection-camera-61839.html")) and Drilling a Hole only Large enough to allow the camera access ??
without the need of removing the Dashboard ??


there is a snorkel access under the plastic cowl screen / cover on the passanger side.  pop the hood and remove wiper arm screen cowl cover.  its very outboard so to speak.  the opening is oval and about 3'' x 2''

or....

you can possibly enter through the floor duct openings,,

or......

remove the dash covering and go into any one of the dash vents

never used a camera system though.
Title: No heat question
Post by: AlabamaWildman on December 03, 2016, 04:14:22 PM
Thank You, Sir !!
Title: No heat question
Post by: softtouch on December 03, 2016, 05:26:29 PM
You could pull out the blower motor resisters. Looks like they are down wind from the AC evaporator.
Turn the ignition off and:
DO NOT RUN THE BLOWER WITH THE RESISTERS PULLED OUT OF THE AIR BOX!! The resisters will over heat and may blow the thermal limiter.
Title: No heat question
Post by: AlabamaWildman on December 03, 2016, 05:52:16 PM
Thanks !! !!
Title: No heat question
Post by: jcassity on December 04, 2016, 09:12:56 AM
if it does thermal, then a small hair of 26ga single strand of copper soldered in place would be the new fuse.  the limiters simply blow like a fuse anyway.
Title: No heat question
Post by: softtouch on December 04, 2016, 10:10:18 AM
Quote from: jcassity;458358
if it does thermal, then a small hair of 26ga single strand of copper soldered in place would be the new fuse.  The limiters simply blow like a fuse anyway.
Wrong, the limiter will blow with the normal amount current draw if the air flow is not moving the resister heat away from the limiter.
Title: No heat question
Post by: AlabamaWildman on December 04, 2016, 12:53:54 PM
Thanks !!

I do not believe this one has any type of "Thermal Imagine"... wish it did
This is only a very small Video Camera
Title: No heat question
Post by: JeremyB on December 04, 2016, 01:03:53 PM
Quote from: softtouch;458353
You could pull out the blower motor resisters. Looks like they are down wind from the AC evaporator.
Turn the ignition off and:
DO NOT RUN THE BLOWER WITH THE RESISTERS PULLED OUT OF THE AIR BOX!! The resisters will over heat and may blow the thermal limiter.
You can run it on high though, right?
Title: No heat question
Post by: softtouch on December 04, 2016, 05:55:14 PM
Quote from: JeremyB;458367
You can run it on high though, right?
Yes
Title: No heat question
Post by: jcassity on December 04, 2016, 06:02:56 PM
Quote from: softtouch;458361
Wrong, the limiter will blow with the normal amount current draw if the air flow is not moving the resister heat away from the limiter.

we are saying the same thing,, when there is a air mover fault the limiter will blow..  thats why the call out for 26awg or smaller to do a make shift repair