#81  
Old 06-12-2021, 02:31 PM
OG68's Avatar
OG68 OG68 is offline
Ultimate Warrior
 
Join Date: Dec 2011
Location: Chula Vista, CA
Posts: 1,475
Default

Weird as it seems the blower motor noise suppressor (cap/choke/flux capacitor lol) came with the FM radio. AM didn't have it. Most of the originals have probably dried up after 50 years.

__________________
Ed

1968 GTO (Thanks Mom)
2006 Silverado
2007 Cadillac SRX
2015 Chevy Express

  #82  
Old 08-10-2021, 09:08 PM
1980 TA 1980 TA is offline
Senior Chief
 
Join Date: Jun 2004
Location: Rolla, MO
Posts: 353
Default

I bought a PM136 fan to try and when I pulled it out of the box the fan was 1/2 to 3/4 shorter than the stock fan on my 1979 Trans AM. I didn't try it so I can't comment on how well it may or may not have worked. I felt it was too short.

  #83  
Old 08-15-2021, 09:49 AM
roger1's Avatar
roger1 roger1 is offline
Chief Ponti-yacker
 
Join Date: Aug 2020
Location: San Angelo, TX
Posts: 765
Default

Quote:
Originally Posted by dataway View Post
Not sure about the GP part, but the A body case has a dish in the passage from the blower to evap to clear the wheel well I think. Seems like a "taller" case would need even more of a dish in it. Although it's a modification that probably wouldn't be too hard to make.
I managed to find a Grand Prix evap box at a super good price so I bought it just to see how it would fit.
You were right Johnny, it would need modifications to fit a GTO. It bolts to the firewall perfectly but there's not enough clearance to the inner fender without that relief that the stock box has. I really don't want to spend the time it would take to do the modification so I am just going to go with the Astro Van motor like you did.

The seller also sent the squirrel cage fan with the box and it's a metal one in extremely good condition. Also the motor cooling hose and it's in really good condition as well. I will sell it all to anyone here for the same price I paid ($35+shipping) that may want to take the time it would take to do the modification. If anyone here is interested, let me know and I will post a couple photos of the parts.

__________________
'69 GTO Convertible - Acquired October 2020. An all original project car. Restomod is underway PROJECT THREAD
'83 Chevy Choo Choo SS El Camino - LT1 350/4L60e, Owned for 30 Years, completed 2nd restomod in 2018 PHOTO
2019 BMW 440ix - Twin turbo I6, 8spd auto. PHOTO
'55 Chevy Bel Air Sport Coupe - Ram Jet 350 / T56 Magnum 6spd, Restomod Completed Sept. 2012, Sold Sept. 2021 PHOTO
  #84  
Old 08-15-2021, 07:09 PM
Formulabruce's Avatar
Formulabruce Formulabruce is offline
Ultimate Warrior
 
Join Date: Nov 2004
Location: North East of AMES PERFORMANCE, in the "SHIRE"
Posts: 9,363
Default

Hi speed on a ac car has a 30 amp "breaker" to the blower motor in that position. It is usually a fuseable link bolted to your alternator output.

__________________
"The Future Belongs to those who are STILL Willing to get their Hands Dirty" .. my Grandfather
  #85  
Old 10-01-2022, 04:30 PM
tallrandyb's Avatar
tallrandyb tallrandyb is offline
Senior Member
 
Join Date: Oct 2020
Location: Orlando Florida area
Posts: 216
Question

Quote:
Originally Posted by aceaceca View Post
My 65 is an original family owned car. The AC renovation I am currently doing is one of the last systems on the car that I have not done. This time, I had both inner and outer plenum boxes off the car. I replaced the two inner vacuum motors on the inside. One opens the defrost door and the other one controls two doors in tandem. It swings a door to divert the incoming air from the evaporator so it does not go to the heater core and at the same time opens the door to direct air to the AC outlets via a secondary plenum box that attaches to the front of the heater/AC plenum. The two doors are connected via a long rod on the top of the heater plenum box.
Ace, reviving this thread and to see what you might remember and/or what anyone else knows (anybody up for a deep vacuum system discussion?).

I've got my dash apart and am checking the vacuum system. The 5 vacuum lines to the dash switch are numbered in order 1-5, and I'm trying to make sense of which lines are pulling vacuum on which diaphragm. Attached is a markup of the 65 vacuum system with my notes.

My statement at the top that the (1) vacuum circuit somehow also feeds vacuum to the (5) circuit is clearly wrong, since the Evaporator (1) (AC) door is controlled by the bar connected to the Diverter (5) (Vent) door.

I know the Defrost (4) door is controlled by the diaphragm by the drivers feet (mine is dead, confirmed with vac pump).

So what does vacuum line (1) actually pull on? 1 and 2 both go to the diaphragm in the engine compartment. If I pull vac on 1, that works fine (but I don't see anything move). If I pull vac on 2, I don't get vac (like a dead diaphragm). BUT, if I block 1 (at the switch) and then pull vac on 2, I see the diaphragm pull in the engine compartment, and I'm assuming that is moving the inside/outside air door.

So when vacuum is applied to vacuum connectors on the switch:

1: what does vacuum pull on? This and 2 both go to the engine compartment diaphragm. I originally thought this had to be the AC evaporator (deflector) door

2: inside/outside door (when hose/connector to port 1 is sealed off at switch)

3: engine vacuum feed (with one-way check valve)

4: Defrost door

5: Vent (diverter) door that also moves Evaporator (deflector) door

Thanks for any help/discussion! My AC is working well, blowing cold when switched on, etc so it appears at this point that all diaphragms are working except the Defrost door, but I can't see how to remove/replace that without removing the entire heater plenum? Good thing I live in Florida!

Thanks.
Attached Thumbnails
Click image for larger version

Name:	65 AC Vacuum Markup.jpg
Views:	113
Size:	50.1 KB
ID:	599694  

  #86  
Old 10-01-2022, 06:36 PM
gto4ben gto4ben is offline
Senior Member
 
Join Date: Aug 2006
Location: Los Angeles, CA
Posts: 192
Default

67 AC systems are similar. If I understand your request correctly, you need clarification on which lines have vacuum per function. See the table to the left on the 1st photo.

With regards to the dual port vacuum motor, this may help wrt a perceived bleeding from another user's question:

"Vent or Out" applies vacuum to both Vacuum Motor nipples, pulling about 7/8" against the spring and opening the Air Inlet Door for 100% outside air.
"Inside" applies vacuum only to the outside nipple. It only moves the Air Inlet Door about 1/8" to meet the 80% recirculated/ 20% outside air. If this malfunctions, you'll get 100% recirculated air.
If your new vacuum motor is bleeding from the outside nipple and cannot hold it's position at 1/8", it may be defective. I have two original vacuum motors and bench tested them to the conditions above and did not see any bleeding. I've attached pictures of the measured positions.
Attached Thumbnails
Click image for larger version

Name:	GTO hose color coding and lengths A.jpg
Views:	111
Size:	50.5 KB
ID:	599697   Click image for larger version

Name:	Motor1, No Vac.jpg
Views:	136
Size:	42.0 KB
ID:	599698   Click image for larger version

Name:	Motor1, Vac Both Nipples.jpg
Views:	99
Size:	41.1 KB
ID:	599699   Click image for larger version

Name:	Motor1, Vac Outside Nipple.jpg
Views:	119
Size:	43.6 KB
ID:	599700  

  #87  
Old 10-01-2022, 06:37 PM
gto4ben gto4ben is offline
Senior Member
 
Join Date: Aug 2006
Location: Los Angeles, CA
Posts: 192
Default

More photos of the second vacuum motor behavior. Keep in mind that the plenum spring pulls the vacuum motor plunger out a little for the no vac condition.
Attached Thumbnails
Click image for larger version

Name:	Motor2, Vac Both Nipples.jpg
Views:	102
Size:	40.9 KB
ID:	599702   Click image for larger version

Name:	Motor2, Vac Outside Nipple.jpg
Views:	99
Size:	44.0 KB
ID:	599703   Click image for larger version

Name:	Motor2. No Vac.jpg
Views:	92
Size:	45.5 KB
ID:	599704  


Last edited by gto4ben; 10-01-2022 at 06:49 PM.
  #88  
Old 10-01-2022, 06:49 PM
hgerhardt's Avatar
hgerhardt hgerhardt is offline
Chief Ponti-yacker
 
Join Date: Dec 2003
Location: CA
Posts: 654
Default

Below are the vacuum circuits for a '66-67, which is essentially the same as your '65 as to the vacuum lines. The diaphragm in the engine compartment either goes full travel for "outside" air or partial travel for "inside" air. Note that "inside" still has some outside air (I guess because everybody smoked back then?). "Off" is no outside airflow.

Notice how each diagram also shows how the vacuum switch routes the vacuum.

Also notice that "outside" has vacuum to both ports. "Inside" has vacuum to only the offset port.
Attached Thumbnails
Click image for larger version

Name:	off.jpg
Views:	113
Size:	36.4 KB
ID:	599705   Click image for larger version

Name:	de-ice.jpg
Views:	110
Size:	39.6 KB
ID:	599706   Click image for larger version

Name:	heat.jpg
Views:	119
Size:	44.9 KB
ID:	599707   Click image for larger version

Name:	out.jpg
Views:	109
Size:	40.2 KB
ID:	599708   Click image for larger version

Name:	in.jpg
Views:	110
Size:	38.3 KB
ID:	599709  


  #89  
Old 10-02-2022, 10:43 AM
tallrandyb's Avatar
tallrandyb tallrandyb is offline
Senior Member
 
Join Date: Oct 2020
Location: Orlando Florida area
Posts: 216
Default

Wow you guys, those diagrams and the explanations are perfect. I was figuring there was a trick in the "5-port" switch that combined vacuum signals in various settings, but couldn't figure it out just from trying to pull test vacuums on various ports.

The colored diagram with the table is the most helpful, but I'm trying to wrap my head around the logic there, which assumes an X means vacuum applied to that circuit in the 5-port switch (3 always "on" since its engine vacuum):

OFF: Just engine vacuum to the switch

De-Ice: Defroster door (4) and 100% outside air (1 + 2) through heater core based on temp door position, blowing to windshield

Heat: 100% outside air (1 + 2) through heater core based on temp door position, blowing to feet

Vent or Out: Diverter + Deflector door combo (5) and 100% outside air (1 + 2) through Evaporator/Heater core based on temp door position, blowing to Vent system

Inside: Diverter + Deflector door combo (5) and 20% outside air (2 only) through Evaporator/Heater core based on temp door position, but this includes De-Ice (4)? I didn't realize it was going to push air to the dash when in Inside air (recirc) mode; How does air get to the Defroster door when the Diverter door is already full open/blocking the path to the Heater floor vents and the Defroster channel? Some still comes through the Heater core and can get there?

Based on this, I can assume I know why I hear a hissing sound when I push my control all the way to Inside: My 1+2 diaphragm is working fine, my 5 diaphragm is working fine, but my 4 (Defrost) diaphragm is dead, so it's causing a vacuum leak there (I hadn't tried running Defrost and hearing it hiss since I'm in Florida, was only checking Vent, Outside AC and Inside AC most of the time!). I was concerned that what I was hearing what a problem with the engine compartment diaphragm and that I may not be getting proper inside/outside air mixing functions, but I was able to pull vacuum on 2 and see the 1+2 diaphragm bar move from inside the dash (with the 1 port plugged).

SO: from what I can see I can't remove/replace the Defrost diaphragm without pulling the entire heater plenum?

  #90  
Old 10-02-2022, 11:43 AM
gto4ben gto4ben is offline
Senior Member
 
Join Date: Aug 2006
Location: Los Angeles, CA
Posts: 192
Default

If you're dextrous, you may be able to access the defroster vacuum motor nuts from below after removing the deflector. There is a long spring holding the defrost door in its default position that will give you difficulty. I struggled with this and it was off the car.
Attached Thumbnails
Click image for larger version

Name:	Defrost Vacuum Motor Removal.jpg
Views:	120
Size:	83.1 KB
ID:	599752  

  #91  
Old 10-02-2022, 12:20 PM
tallrandyb's Avatar
tallrandyb tallrandyb is offline
Senior Member
 
Join Date: Oct 2020
Location: Orlando Florida area
Posts: 216
Thumbs up

Quote:
Originally Posted by gto4ben View Post
If you're dextrous, you may be able to access the defroster vacuum motor nuts from below after removing the deflector. There is a long spring holding the defrost door in its default position that will give you difficulty. I struggled with this and it was off the car.
LOL I am attempting that right now! I had forgotten that I have the Detroit Iron online 65 Pontiac manuals which also has the AC system manuals, and I'm reading the section: 10-1 Services and Repairs - Mechanical right now. Page 10-5 says that exact same thing.

I currently have a small 1/4" socket on the head of the screw that connects the diaphragm bar to the defroster door, but before I go any further I'm going to look online to see if I can even buy a replacement Delco-Remy diaphragm (everything is on the car, console still in but driver's seat and steering wheel out since I'm doing all the dash work).

Thanks!

  #92  
Old 10-02-2022, 01:00 PM
tallrandyb's Avatar
tallrandyb tallrandyb is offline
Senior Member
 
Join Date: Oct 2020
Location: Orlando Florida area
Posts: 216
Default

Quote:
Originally Posted by tallrandyb View Post
LOL I am attempting that right now! I had forgotten that I have the Detroit Iron online 65 Pontiac manuals which also has the AC system manuals, and I'm reading the section: 10-1 Services and Repairs - Mechanical right now. Page 10-5 says that exact same thing.

I currently have a small 1/4" socket on the head of the screw that connects the diaphragm bar to the defroster door, but before I go any further I'm going to look online to see if I can even buy a replacement Delco-Remy diaphragm (everything is on the car, console still in but driver's seat and steering wheel out since I'm doing all the dash work).

Thanks!
Looks like this may match the single-port diaphragm for Defrost?

https://www.ebay.com/itm/202560973830

  #93  
Old 10-02-2022, 01:28 PM
hgerhardt's Avatar
hgerhardt hgerhardt is offline
Chief Ponti-yacker
 
Join Date: Dec 2003
Location: CA
Posts: 654
Default

A workaround for now is to plug the vacuum hose at the defog actuator. Especially since you live in FL and say you don't need it (much).

  #94  
Old 10-02-2022, 01:30 PM
tallrandyb's Avatar
tallrandyb tallrandyb is offline
Senior Member
 
Join Date: Oct 2020
Location: Orlando Florida area
Posts: 216
Default

Quote:
Originally Posted by hgerhardt View Post
A workaround for now is to plug the vacuum hose at the defog actuator. Especially since you live in FL and say you don't need it (much).
Absolutely! I think I'll do just that right now and then take another shot at that replacement later by itself, I'd just pull the driver's seat again but everything else can stay (except the floor heat deflector, two small screws).

Thanks!

  #95  
Old 08-19-2023, 07:07 PM
roger1's Avatar
roger1 roger1 is offline
Chief Ponti-yacker
 
Join Date: Aug 2020
Location: San Angelo, TX
Posts: 765
Default

Just wanted to mention again that I do have a '69 to '72 Grand Prix evaporator housing that I want to sell. If I don't get any takers, I'll try ebay.
I cleaned it up today and took some photos. It's in really good condition and comes with the fan squirrel cage and motor vent hose. Both of those are in fantastic condition as well. I did lightly blast the squirrel cage and sprayed some aluminum paint on it.








__________________
'69 GTO Convertible - Acquired October 2020. An all original project car. Restomod is underway PROJECT THREAD
'83 Chevy Choo Choo SS El Camino - LT1 350/4L60e, Owned for 30 Years, completed 2nd restomod in 2018 PHOTO
2019 BMW 440ix - Twin turbo I6, 8spd auto. PHOTO
'55 Chevy Bel Air Sport Coupe - Ram Jet 350 / T56 Magnum 6spd, Restomod Completed Sept. 2012, Sold Sept. 2021 PHOTO
The Following User Says Thank You to roger1 For This Useful Post:
  #96  
Old 12-03-2023, 02:15 AM
Tuske427's Avatar
Tuske427 Tuske427 is offline
Member
 
Join Date: Sep 2016
Location: Los Angeles
Posts: 51
Default

Adding onto an old thread here in the hopes that what I did may be of help for others who come across this.

When I got my car earlier this year ('69 GTO w/ AC) there was almost no air coming out of the vents at all even on the high fan setting.

1- One thing I did was seal up the lower AC ducting section that bolts up underneath the dashboard by using plastic weld cement in the insides of the unit. this sealed up all the seams and prevents leaks. I also sealed up all the ducting underneath the dashboard using HVAC tape. including where it meets the firewall. I found this tape to be very thin/ easy to work with and wrap around the ducting connection points to seal up everything. It's all great until I need to take things apart underneath the dash. Pro tip- do this after you think you're finished taking things apart underneath the dash

2- After that and still not being satisfied with the volume of air being moved I started looking into seeing if others had replaced the blower motor with something else more powerful and came across this thread. In the interest of wanting to try all possible options I too ordered the replacement motor recommended here (VDO/Continental PM136) bought it from Amazon, and when received I removed the original blower motor from my car. I then clamped each motor to my vice (one at a time) and tested them with an extra car battery and jumper cables. This is where the big surprise came in- the original motor was noticeably more powerful than the new one. the start up was, well, almost violent for lack of a better term and blew air all over the place. the new motor was like a calm morning slowly gaining speed and moved much less air by comparison. So back that went and the original motor went back in the car.

Now when I removed the blower motor from my car I noticed the cooling tube was missing- meaning that air was just blowing out the hole in the heater core box that should have been feeding air back to my blower motor for cooling. Also, while a previous owner added a ground wire they didn't bother to clean the paint off for bare metal contact. I fixed both of these things when reinstalling. I also then added a bead of RTV silicone around the fan mounting flange to ensure no leaking air when reassembled and then tested the fan motor once reassembled to feel for leaking air. I found a bunch of leaking air up inside the inner fender area where the heater box mounted to the firewall. I then added more RTV silicone to that to seal it up, then put the rest of the car back together and tested it the next day.

Significant improvement! Now all the air that the fan is moving is coming out the vents and not bleeding away into the inner fender.

3- Lastly, this weekend I've further upgraded the car with a higher amp alternator (10si 95 amp internally regulated alternator) and this too seems to help with the fan having more voltage to work with.

The big takeaways here are to seal up the ducting both in front of the firewall and underneath the dash to make sure any/ all air isn't bleeding away from leaks.

hope this helps

__________________
Long live the Muscle Car
Instagram @tuske427
1967 Firebird #BVbird
1967 Firebird 400 4 speed project
1969 Verdoro green GTO (daily)
The Following 3 Users Say Thank You to Tuske427 For This Useful Post:
  #97  
Old 12-04-2023, 03:48 PM
tallrandyb's Avatar
tallrandyb tallrandyb is offline
Senior Member
 
Join Date: Oct 2020
Location: Orlando Florida area
Posts: 216
Default

Quote:
Originally Posted by Tuske427 View Post
Adding onto an old thread here in the hopes that what I did may be of help for others who come across this.

When I got my car earlier this year ('69 GTO w/ AC) there was almost no air coming out of the vents at all even on the high fan setting.

The big takeaways here are to seal up the ducting both in front of the firewall and underneath the dash to make sure any/ all air isn't bleeding away from leaks.

hope this helps
Great post! I did much of the same on my 65 GTO this summer, while reworking the dash control panel/indicators/bulbs/stereo and after removing all the ducting I RTV sealed all the seams where the plastic "rivets" were not really holding the ducts together all that well. Plus I wrapped gorilla tape around every slide-together joint and at the dash ball vents where the tubing slides onto them. Additionally, I had to rebuild my vacuum switch so all the flappers worked correctly and replaced the fan speed switch to insure I was getting full speed all the way up to the High setting. Major improvements and you can feel plenty of cold air blowing on you now, especially on High.

Well worth the time and effort!

The Following User Says Thank You to tallrandyb For This Useful Post:
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 05:17 PM.

 

About Us

The PY Online Forums is the largest online gathering of Pontiac enthusiasts anywhere in the world. Founded in 1991, it was also the first online forum for people to gather and talk about their Pontiacs. Since then, it has become the mecca of Pontiac technical data and knowledge that no other place can surpass.

 




Copyright © 2017