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Re: Not much heat from heater (3/13)
 4/13/18 10:10pm
BillHanna
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Cana, VA - USA

Vette(s):
1975 Stingray


Joined: 7/3/2016
Posts: 163

73shark said: Did you visually verify that the heater valve is open internally? Is it a problem that the air coming out is not hot enough or the air is hot but there's not enough quantity? I drove mine to work daily and in the winter time the heater put out plenty of hot air.



Yes, the heater valve that I put in is a ball type made for a heater hose.
I seem to get good air flow (it seems anyway), but it is not very hot.



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Re: Not much heat from heater (4/13)
 4/13/18 10:58pm
73shark
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Overland Park, KS - USA

Vette(s):
1973 Orange Metallic Coupe (orig owner), L82, 4 spd (WR), PS, (A/C & PW (I installed from wrecked 73)), leather, AM/FM Stereo, ran with '65 FI unit earlier & will again some day.


Joined: 7/9/2003
Posts: 554

Try checking the temperature of the hose going in and the hose going out and see if there's any big difference. You can get one of those inexpensive laser temperature guns at Harbor Freight if you don't have one. I assume that the hoses are free and clear.

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1973 L-82 4 spd

Re: Not much heat from heater (5/13)
 4/16/18 5:11pm
BillHanna
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Cana, VA - USA

Vette(s):
1975 Stingray


Joined: 7/3/2016
Posts: 163

73shark said: Try checking the temperature of the hose going in and the hose going out and see if there's any big difference. You can get one of those inexpensive laser temperature guns at Harbor Freight if you don't have one. I assume that the hoses are free and clear.

I bought a laser temp gun:  The temperature difference between the inlet and outlet heater hoses is about 10 degrees with the heater fan on high.

Checking the temp at the heater air outlet at the passenger side is about 130 degrees (anyone know if this is about right?)  The driver's side is about ten degrees cooler.

How much trouble is it to pull the heater core?



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Re: Not much heat from heater (6/13)
 4/16/18 9:49pm
F4Gary
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Grapevine, TX - USA

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1972 LT-1 convertible with factory air.


Joined: 8/26/2006
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That is certainly hot enough to heat the cabin.

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Re: Not much heat from heater (7/13)
 4/16/18 10:41pm
73shark
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Overland Park, KS - USA

Vette(s):
1973 Orange Metallic Coupe (orig owner), L82, 4 spd (WR), PS, (A/C & PW (I installed from wrecked 73)), leather, AM/FM Stereo, ran with '65 FI unit earlier & will again some day.


Joined: 7/9/2003
Posts: 554

As one that installed factory A/C in mine, I'll say it's medium difficulty.  IIRC, you have to do it from the inside.

What was the temp. of inlet hose? 

If 130* air is heating the interior, then maybe you're not getting enuf air flow.

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1973 L-82 4 spd

Re: Not much heat from heater (8/13)
 4/18/18 8:16pm
BillHanna
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Cana, VA - USA

Vette(s):
1975 Stingray


Joined: 7/3/2016
Posts: 163

73shark said: As one that installed factory A/C in mine, I'll say it's medium difficulty.  IIRC, you have to do it from the inside.

What was the temp. of inlet hose? 

If 130* air is heating the interior, then maybe you're not getting enuf air flow.

I wonder if when they removed the A/C (assuming they did go inside it -- it looks like the fittings are still jutting out of the housing) they did something to disrupt the airflow in the heater box.




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Re: Not much heat from heater (9/13)
 4/18/18 8:48pm
73shark
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Overland Park, KS - USA

Vette(s):
1973 Orange Metallic Coupe (orig owner), L82, 4 spd (WR), PS, (A/C & PW (I installed from wrecked 73)), leather, AM/FM Stereo, ran with '65 FI unit earlier & will again some day.


Joined: 7/9/2003
Posts: 554

If the evaporator is still in the housing, then perhaps it's clogged w/ debris, mold, and/or mildew.  You can open the housing up w/o removing the engine and check the evaporator.  Not sure why they would've disabled the A/C.  Ermm

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1973 L-82 4 spd

Re: Not much heat from heater (10/13)
 4/24/18 11:22am
danascar
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Germansville, PA - USA

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1974 Coupe 358ci 4 speed Black w/Medium Saddle interior w/79 custom leather seats. . 1999 Covertible, 6 speed, Atomic orange, Oak interior


Joined: 1/28/2010
Posts: 803

As long as you don't have a run hot problem you might want to change to a 195 degree t-stat. 165 is on the cool side.  

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Dan T
 

Re: Not much heat from heater (11/13)
 4/24/18 8:24pm
stingrayjim jrLifetime Member
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SHELBYVILLE, TN - USA

Vette(s):
1976 L48 auto

1978 L82 4speed

1994 LT1 6speed


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just a thought, as i did not notice anyone mentioning this, and sorry if i missed it if they did mention the blend door.  Its a door within the duct that diverts the air from either the a/c evaporator and/or the heater core.... so it doesn't blow hot air when the a/c is on, or cold air with the heater on....  if you took the map pouch panel off, you'd see the lever on top of the duct.   I have had issue with the wire going to it come off, or not work at all when you roll the heater selector....   i'll link a video showing how to replace the heater core, and you can see the small lever with the wire(push/pull type wire) that opens/closes the blend door... it can be seen around the 3 minute mark...   http://https://www.youtube.com/watch?v=83s8HnUPcIU 

https://www.youtube.com/watch?v=83s8HnUPcIU


|UPDATED|4/24/2018 5:24:28 PM (AZT)|/UPDATED|
Re: Not much heat from heater (12/13)
 4/24/18 9:27pm
BillHanna
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Cana, VA - USA

Vette(s):
1975 Stingray


Joined: 7/3/2016
Posts: 163

stingrayjim jr said: just a thought, as i did not notice anyone mentioning this, and sorry if i missed it if they did mention the blend door.  Its a door within the duct that diverts the air from either the a/c evaporator and/or the heater core.... so it doesn't blow hot air when the a/c is on, or cold air with the heater on....  if you took the map pouch panel off, you'd see the lever on top of the duct.   I have had issue with the wire going to it come off, or not work at all when you roll the heater selector....   i'll link a video showing how to replace the heater core, and you can see the small lever with the wire(push/pull type wire) that opens/closes the blend door... it can be seen around the 3 minute mark...   http://https://www.youtube.com/watch?v=83s8HnUPcIU 

https://www.youtube.com/watch?v=83s8HnUPcIU




Thanks!  I'll check that soon as I can.



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Re: Not much heat from heater (13/13)
 4/27/18 8:36pm
BillHanna
Standard Member
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Cana, VA - USA

Vette(s):
1975 Stingray


Joined: 7/3/2016
Posts: 163

stingrayjim jr said: just a thought, as i did not notice anyone mentioning this, and sorry if i missed it if they did mention the blend door.  Its a door within the duct that diverts the air from either the a/c evaporator and/or the heater core.... so it doesn't blow hot air when the a/c is on, or cold air with the heater on....  if you took the map pouch panel off, you'd see the lever on top of the duct.   I have had issue with the wire going to it come off, or not work at all when you roll the heater selector....   i'll link a video showing how to replace the heater core, and you can see the small lever with the wire(push/pull type wire) that opens/closes the blend door... it can be seen around the 3 minute mark...   http://https://www.youtube.com/watch?v=83s8HnUPcIU 

https://www.youtube.com/watch?v=83s8HnUPcIU





Okay, I pulled the right-side dash and found the lever.  The cable is hooked to it, and it did move when I moved the heater controls, but after a bit it no longer moved.  Don't know why.
I did notice that the vent to the left front on the heater box did not move at all.  I assume this opens depending on the vent setting to direct heat to the front ducts (the duct work is missing on this car).  I could open it manually, and felt air coming from the opening.  I assume with this closed the air is going mostly to the defroster vent.  Not sure if there is a vacuum issue or what. . .

I'll try to post a picture of the vent I'm talking about:



Wow, I actually got an image uploaded. . . 



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