Anyone ever put a 78 dash heater/AC in a 73?
- Thread starter Bob Dunahugh
- Start date
Once you incur the trouble of taking it apart and out, why not customize the replacement to your liking?
--johnny
--
76 26' Eleganza(?) with beaucoup mods and add - ons.
Braselton, Ga.
"I forgive them all, save those who hurt the dogs. They must answer to me in hell" - ol Andy, paraphrased
--johnny
--
76 26' Eleganza(?) with beaucoup mods and add - ons.
Braselton, Ga.
"I forgive them all, save those who hurt the dogs. They must answer to me in hell" - ol Andy, paraphrased
I could be wrong, but it is not just the external hvac box that is different, but the ducting in the dash. I dont think it would be feasable
without destroying the dash and rebuilding.
Look at the write up tom pryor just had on the forum adding a dual fan/blower to fix the hvac problems. I think he has something with that and am
planning on doing that to my 75.
--
Jon Roche
75 palm beach
St. Cloud, MN
http://lqqkatjon.blogspot.com/
without destroying the dash and rebuilding.
Look at the write up tom pryor just had on the forum adding a dual fan/blower to fix the hvac problems. I think he has something with that and am
planning on doing that to my 75.
--
Jon Roche
75 palm beach
St. Cloud, MN
http://lqqkatjon.blogspot.com/
Most of these coach dashes are held together by bailing wire and dum-dum
putty regardless of what year model they are. They all squeak and rattle,
the vacuum doors are non functioning or the felt flap seals are missing or
deteriorated so bad that they leak badly. Combine that with dash controls
and vacuum hoses that are in poor shape, and you get the picture. The
heat/defrost/Air conditioning has deteriorated to the point of non
functioning. The fix???? Rip it all out and rebuild it all. Not a job for
the faint of heart. Band-Aids won't work here, neither will mickey mouse
fixes. Spend some money and do it the best way possible. You won't regret
it.
Jim Hupy
Salem, Or
78 GMC ROYALE 403
I could be wrong, but it is not just the external hvac box that is
different, but the ducting in the dash. I dont think it would be feasable
without destroying the dash and rebuilding.
Look at the write up tom pryor just had on the forum adding a dual
fan/blower to fix the hvac problems. I think he has something with that
and am
planning on doing that to my 75.
--
Jon Roche
75 palm beach
St. Cloud, MN
http://lqqkatjon.blogspot.com/
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putty regardless of what year model they are. They all squeak and rattle,
the vacuum doors are non functioning or the felt flap seals are missing or
deteriorated so bad that they leak badly. Combine that with dash controls
and vacuum hoses that are in poor shape, and you get the picture. The
heat/defrost/Air conditioning has deteriorated to the point of non
functioning. The fix???? Rip it all out and rebuild it all. Not a job for
the faint of heart. Band-Aids won't work here, neither will mickey mouse
fixes. Spend some money and do it the best way possible. You won't regret
it.
Jim Hupy
Salem, Or
78 GMC ROYALE 403
I could be wrong, but it is not just the external hvac box that is
different, but the ducting in the dash. I dont think it would be feasable
without destroying the dash and rebuilding.
Look at the write up tom pryor just had on the forum adding a dual
fan/blower to fix the hvac problems. I think he has something with that
and am
planning on doing that to my 75.
--
Jon Roche
75 palm beach
St. Cloud, MN
http://lqqkatjon.blogspot.com/
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
Contact either of the Jims or Vintage Air. 
All 3 of them make excellent
fixes for the GMC dash HVAC.
Sammy
> Most of these coach dashes are held together by bailing wire and dum-dum
> putty regardless of what year model they are. They all squeak and rattle,
> the vacuum doors are non functioning or the felt flap seals are missing or
> deteriorated so bad that they leak badly. Combine that with dash controls
> and vacuum hoses that are in poor shape, and you get the picture. The
> heat/defrost/Air conditioning has deteriorated to the point of non
> functioning. The fix???? Rip it all out and rebuild it all. Not a job for
> the faint of heart. Band-Aids won't work here, neither will mickey mouse
> fixes. Spend some money and do it the best way possible. You won't regret
> it.
> Jim Hupy
> Salem, Or
> 78 GMC ROYALE 403
>
>
> I could be wrong, but it is not just the external hvac box that is
> different, but the ducting in the dash. I dont think it would be feasable
> without destroying the dash and rebuilding.
>
> Look at the write up tom pryor just had on the forum adding a dual
> fan/blower to fix the hvac problems. I think he has something with that
> and am
> planning on doing that to my 75.
>
>
> --
> Jon Roche
> 75 palm beach
> St. Cloud, MN
> http://lqqkatjon.blogspot.com/
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
All 3 of them make excellentfixes for the GMC dash HVAC.
Sammy
> Most of these coach dashes are held together by bailing wire and dum-dum
> putty regardless of what year model they are. They all squeak and rattle,
> the vacuum doors are non functioning or the felt flap seals are missing or
> deteriorated so bad that they leak badly. Combine that with dash controls
> and vacuum hoses that are in poor shape, and you get the picture. The
> heat/defrost/Air conditioning has deteriorated to the point of non
> functioning. The fix???? Rip it all out and rebuild it all. Not a job for
> the faint of heart. Band-Aids won't work here, neither will mickey mouse
> fixes. Spend some money and do it the best way possible. You won't regret
> it.
> Jim Hupy
> Salem, Or
> 78 GMC ROYALE 403
>
>
> I could be wrong, but it is not just the external hvac box that is
> different, but the ducting in the dash. I dont think it would be feasable
> without destroying the dash and rebuilding.
>
> Look at the write up tom pryor just had on the forum adding a dual
> fan/blower to fix the hvac problems. I think he has something with that
> and am
> planning on doing that to my 75.
>
>
> --
> Jon Roche
> 75 palm beach
> St. Cloud, MN
> http://lqqkatjon.blogspot.com/
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
G'day,
I have an auxiliary under dash unit built by Vintage Air in Double Trouble and it provides heaps of extra cooling and keeps the
cockpit area comfortable; however, it has two downsides:
1) the vents will not direct cooling airflow directly onto the driver or passenger.
2) the twin 3 inch squirrel cage blowers on a single motor turns very fast to move the airflow and is noisy.
I intend to replace it with a mid 1960's Mustang under dash unit which has twin 5 inch squirrel cage blowers turns slower and is
much quieter.
They turn up on eBay quite regularly:
Tiny URL: http://tinyurl.com/y9ayvpa9
Full URL:
http://www.ebay.com/itm/1964-66-Ford-Falcon-Mustang-underdash-A-C-air-conditioning-unit-blower-works-/202012284935?hash=item2f08ded8
07:g:JPEAAOSwAr9Zh3K~&vxp=mtr
Note the size of the blowers!
Regards,
Rob M.
Sydney, Australia
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426
USA '77 Kingsley - TZE 267V100808
-----Original Message-----
From: Gmclist [mailto:gmclist-bounces] On Behalf Of Sammy Williams
Sent: Wednesday, August 9, 2017 8:12 AM
To: gmclist
Subject: Re: [GMCnet] Anyone ever put a 78 dash heater/AC in a 73?
Contact either of the Jims or Vintage Air. All 3 of them make excellent
fixes for the GMC dash HVAC.
Sammy
I have an auxiliary under dash unit built by Vintage Air in Double Trouble and it provides heaps of extra cooling and keeps the
cockpit area comfortable; however, it has two downsides:
1) the vents will not direct cooling airflow directly onto the driver or passenger.
2) the twin 3 inch squirrel cage blowers on a single motor turns very fast to move the airflow and is noisy.
I intend to replace it with a mid 1960's Mustang under dash unit which has twin 5 inch squirrel cage blowers turns slower and is
much quieter.
They turn up on eBay quite regularly:
Tiny URL: http://tinyurl.com/y9ayvpa9
Full URL:
http://www.ebay.com/itm/1964-66-Ford-Falcon-Mustang-underdash-A-C-air-conditioning-unit-blower-works-/202012284935?hash=item2f08ded8
07:g:JPEAAOSwAr9Zh3K~&vxp=mtr
Note the size of the blowers!
Regards,
Rob M.
Sydney, Australia
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426
USA '77 Kingsley - TZE 267V100808
-----Original Message-----
From: Gmclist [mailto:gmclist-bounces] On Behalf Of Sammy Williams
Sent: Wednesday, August 9, 2017 8:12 AM
To: gmclist
Subject: Re: [GMCnet] Anyone ever put a 78 dash heater/AC in a 73?
Contact either of the Jims or Vintage Air.
All 3 of them make excellentfixes for the GMC dash HVAC.
Sammy
I have plenty of 78 parts. So I'm putting in a complete 78 Royale rear bath interior, and all windows. Complete 78 rear suspension with the air ride controls, and compressor. The 78 taller rear inter fender wells. So when done. I want it to have all the 78 up grades included. With new furnace, roof A/C, frig, and cook top. Thus it will be a 78 Royale with a 73 body shell only.
Bob Dunahugh
Bob Dunahugh
For grins, I drew up some diagrams of 73/74, 75/76, and 77/78 hvac boxes and ducts that I've seen.
It's not to scale and I don't have some of the angles right (eg the heater core mounted at an angle)
but it should give an idea of the changes and airflow:
http://www.gmcmhphotos.com/photos/original-details/p63520-hvac-air-conditioner-ac-heater-evaporator-box-changes.html
The "Separating Hot from Cold" article by Jay Brand mostly focuses on the 77/78 and is a little misleading
for prior years because the dash ducting is completely different.
Karen
1975 26'
It's not to scale and I don't have some of the angles right (eg the heater core mounted at an angle)
but it should give an idea of the changes and airflow:
http://www.gmcmhphotos.com/photos/original-details/p63520-hvac-air-conditioner-ac-heater-evaporator-box-changes.html
The "Separating Hot from Cold" article by Jay Brand mostly focuses on the 77/78 and is a little misleading
for prior years because the dash ducting is completely different.
Karen
1975 26'
I have never installed a 77'78 in another model, but I know you'll need to
also replace the control panel.
> For grins, I drew up some diagrams of 73/74, 75/76, and 77/78 hvac boxes
> and ducts that I've seen.
> It's not to scale and I don't have some of the angles right (eg the heater
> core mounted at an angle)
> but it should give an idea of the changes and airflow:
> http://www.gmcmhphotos.com/photos/original-details/
> p63520-hvac-air-conditioner-ac-heater-evaporator-box-changes.html
>
> The "Separating Hot from Cold" article by Jay Brand mostly focuses on the
> 77/78 and is a little misleading
> for prior years because the dash ducting is completely different.
>
> Karen
> 1975 26'
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
--
Jim Kanomata
Applied/GMC, Newark,CA
jimk
http://www.appliedgmc.com
1-800-752-7502
also replace the control panel.
> For grins, I drew up some diagrams of 73/74, 75/76, and 77/78 hvac boxes
> and ducts that I've seen.
> It's not to scale and I don't have some of the angles right (eg the heater
> core mounted at an angle)
> but it should give an idea of the changes and airflow:
> http://www.gmcmhphotos.com/photos/original-details/
> p63520-hvac-air-conditioner-ac-heater-evaporator-box-changes.html
>
> The "Separating Hot from Cold" article by Jay Brand mostly focuses on the
> 77/78 and is a little misleading
> for prior years because the dash ducting is completely different.
>
> Karen
> 1975 26'
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
--
Jim Kanomata
Applied/GMC, Newark,CA
jimk
http://www.appliedgmc.com
1-800-752-7502
> I have never installed a 77'78 in another model, but I know you'll need to
> also replace the control panel.
That makes sense since it uses a whole new ducting system with vacuum pots in different places.
Since it's a bit hard to read the big picture, it was requested I add separate images for each model year:
73/74:
http://www.gmcmhphotos.com/photos/original-details/p63523-hvac-air-conditioner-ac-heater-evaporator-box-changes-each-model-year.html
76/76:
http://www.gmcmhphotos.com/photos/original-details/p63524-hvac-air-conditioner-ac-heater-evaporator-box-changes-each-model-year.html
77/78:
http://www.gmcmhphotos.com/photos/original-details/p63525-hvac-air-conditioner-ac-heater-evaporator-box-changes-each-model-year.html
I also noticed some errant text in the 75/76 drawing, so fixed that.
Karen
1875 26'
> also replace the control panel.
That makes sense since it uses a whole new ducting system with vacuum pots in different places.
Since it's a bit hard to read the big picture, it was requested I add separate images for each model year:
73/74:
http://www.gmcmhphotos.com/photos/original-details/p63523-hvac-air-conditioner-ac-heater-evaporator-box-changes-each-model-year.html
76/76:
http://www.gmcmhphotos.com/photos/original-details/p63524-hvac-air-conditioner-ac-heater-evaporator-box-changes-each-model-year.html
77/78:
http://www.gmcmhphotos.com/photos/original-details/p63525-hvac-air-conditioner-ac-heater-evaporator-box-changes-each-model-year.html
I also noticed some errant text in the 75/76 drawing, so fixed that.
Karen
1875 26'
Nice job, Karen & very helpful. I am trying to figure out what to do to the stretch... Buskirk put in some different ducting, but it is just a
relocation of the 78 outlets. We do need more air! I am looking at doing the mod outlined by Tom Pryor, but do not have it clear how the 78 extra
heater outlet under the dash will fit with that mod.
--
John Shutzbaugh, Vacaville, CA, ncserv;
77 Eleganza, bought it new, can't blame PO, and
78 Buskirk stretch, "What were we thinking?"
relocation of the 78 outlets. We do need more air! I am looking at doing the mod outlined by Tom Pryor, but do not have it clear how the 78 extra
heater outlet under the dash will fit with that mod.
--
John Shutzbaugh, Vacaville, CA, ncserv;
77 Eleganza, bought it new, can't blame PO, and
78 Buskirk stretch, "What were we thinking?"
