#1  
Old 06-12-2021, 05:52 PM
tallrandyb's Avatar
tallrandyb tallrandyb is offline
Senior Member
 
Join Date: Oct 2020
Location: Orlando Florida area
Posts: 216
Question 1965 AC switches question

My car has a couple of "bypass" switches mounted under the dash that energize the compressor and provide power to the air conditioning relay on the firewall (this one makes the fan run at one speed since it is skipping the fan speed switch functions).

According to the wiring diagram, the "clutch control" switch assembly should activate the first, and the "master switch" assembly should control the second.

These two are located in the dash behind the heater/AC controls, correct? And can I get to these to insure the wires are properly connected and put a meter on them to check continuity/etc without having to remove the entire dash? Can I remove the glovebox and/or radio and get to them from below/the side?

I'd like to get the system working correctly from the dash controls, and want to be sure I'm looking at the right things and in the right place.

Thanks!
Attached Thumbnails
Click image for larger version

Name:	AC.controls.diagram2.jpg
Views:	97
Size:	89.3 KB
ID:	568094   Click image for larger version

Name:	AC.controls.diagram3.jpg
Views:	72
Size:	70.6 KB
ID:	568095  

  #2  
Old 06-12-2021, 06:16 PM
Jeff Hamlin's Avatar
Jeff Hamlin Jeff Hamlin is offline
Ultimate Warrior
 
Join Date: Jan 2000
Location: Beach side of Virginia
Posts: 9,371
Default

That's a tough one, You may be able to access them with the glove box out to at least check the connections,
but if they need to be replaced you will likely have to take the control panel out.

The image below is '66 but is similar for a visual.
Attached Thumbnails
Click image for larger version

Name:	66 AC CONTROLS 8.jpg
Views:	75
Size:	75.7 KB
ID:	568096  

__________________
When I die, I want to go peacefully like my grandfather did, in his sleep.
Not screaming like the passengers in his car.
  #3  
Old 06-12-2021, 06:34 PM
tallrandyb's Avatar
tallrandyb tallrandyb is offline
Senior Member
 
Join Date: Oct 2020
Location: Orlando Florida area
Posts: 216
Default

Thanks Jeff. Does anybody make/sell those two replacement switches? I looked through the Ames catalog but didn’t see any.

I would anything to not have to pull the full dash, but if I have to I will.

But at least now I know what to look for/check the wiring on!

  #4  
Old 06-13-2021, 07:50 AM
Jeff Hamlin's Avatar
Jeff Hamlin Jeff Hamlin is offline
Ultimate Warrior
 
Join Date: Jan 2000
Location: Beach side of Virginia
Posts: 9,371
Default

I'm not aware of any AC control switch offerings beyond old stock.
I was able to clean all my OE switches and re-use them but have randomly secured NOS off the internet here and there.

__________________
When I die, I want to go peacefully like my grandfather did, in his sleep.
Not screaming like the passengers in his car.
  #5  
Old 06-16-2021, 12:01 PM
tallrandyb's Avatar
tallrandyb tallrandyb is offline
Senior Member
 
Join Date: Oct 2020
Location: Orlando Florida area
Posts: 216
Question

Photos and questions!

Here are the two switches in question. The one towards the back of the AC control appears to activate when in all positions except OFF for the AC/heat/vent control (I can see the dash controller move the contacts when moving left from Off and Right from off). The other one nearer the vacuum block that is actuated by the cam in the photo is the clutch control switch, which appears to break contact only when the AC/heat/vent control is in Inside or Outside (AC) positions. Otherwise it looks like it should be in contact.

First: are these two pictures/switch identifications correct (I assume so)?

Second: I would think that the clutch control switch would be in a disconnected state until the dash controller is moved to Inside/Outside AC only, when it would then energize the wire running to the compressor solenoid. But the way the cam moves and that clutch switch element moves, it looks like it moves those two surfaces _apart_ which I assume breaks the circuit (right now I don't get any continuity across the two wire connectors regardless of physical control switch position, maybe the contact surfaces need to be adjusted somewhat to get the open/closed gaps set correctly)? I'm still investigating continuity/etc there.

Third: For the master control switch, I assume the grey wire running out of the switch (brown is power in, grey would be power out) should be running straight to the Master hi-speed relay (according to 65 wiring diagram), which then activates that circuit and then the speed control switch takes over the choices of which resistor(s) to use in the circuit to control blower speed? Right now it is spliced into other grey wires which one looks like they are also the light bulb grey wire for the AC controller panel. Since there is a "cheat" wire feeding power to the hi-speed relay from under the dash (when flipped), this grey wire likely isn't doing anything right now, not sure why it would be spliced into the lighting "grey" circuit.

Kind of a mess trying to sort this out, with the "cheat" circuits wired in and I'm trying to get it back to correct and working from just the dash switches. Everything else (cabling, vacuum, etc) all looks good so it may have been that one or both of these switches stopped working so they just kind of "hardwired" in two switches under the dash instead of pulling it all apart to fix it quick. The switches move correctly from cam rotation contact so I'll continue to check continuity through them and confirm the brown wires to both are getting power with key on.

Thanks for any help!!!
Attached Thumbnails
Click image for larger version

Name:	65 AC master control switch.jpg
Views:	66
Size:	50.3 KB
ID:	568324   Click image for larger version

Name:	65 AC clutch control switch.jpg
Views:	72
Size:	82.1 KB
ID:	568325  

  #6  
Old 06-20-2021, 01:32 PM
donziboy's Avatar
donziboy donziboy is offline
Member
 
Join Date: Feb 2008
Location: Lancaster, Pa
Posts: 65
Default

This drawing should help you with trouble shooting although it for 1968 it’s correct for my 65 except for the ambient switch. My problem was the orange circuit to the master switch that during troubleshooting I determined was bad and kept blowing the fuse at the main fuse block when I turned the key on. Pontiac designed this so the blower always ran once the ignition was in the on or run position. I bypassed the master switch and installed a toggle switch and now the system works with it when its in the on position and the fuse is good now. For me I’m good with this configuration because if I don’t want the original blower running I can flip the switch off.
Bob
Attached Thumbnails
Click image for larger version

Name:	26458549-8C3D-4B41-8F6B-B6CF1FA9B57F.jpg
Views:	60
Size:	67.6 KB
ID:	568513   Click image for larger version

Name:	28E77A6A-499A-420B-8511-D35B996C5BEE.jpg
Views:	62
Size:	42.9 KB
ID:	568514  

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 09:51 AM.

 

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