Riviera63 Posted June 3, 2023 Share Posted June 3, 2023 (edited) Should have asked this first. Is there any way to test the switch to see if it is good? AC stopped working this spring. Hoses are newer and in the right spots. The vacuum diaphragm on the firewall is functioning. Next stop the vacuum switch. I know this is a tough find but, I am looking for the #1 Vaccum switch which is activated by the the AC Cool Control lever. I believe that the number for this is: 1164645. Please correct me if I am wrong on the number. Good used or NOS is fine. High 80's for the past week and looking to continue. Not essential but, it would be nice to have working AC once in awhile. PM me if you can help me out. Thanks. Bill Edited June 3, 2023 by Riviera63 (see edit history) Link to comment Share on other sites More sharing options...
Jim Cannon Posted June 3, 2023 Share Posted June 3, 2023 Bill- I have had good luck with the "vacuum switches", as Buick called them, by giving a shot of silicon spray into the nipple and then actuating the switch with your fingers repeatedly. That gets them moving and sealing again. You may need to spray again in a year, but they will work. Link to comment Share on other sites More sharing options...
Riviera63 Posted June 3, 2023 Author Share Posted June 3, 2023 (edited) 52 minutes ago, Jim Cannon said: Bill- I have had good luck with the "vacuum switches", as Buick called them, by giving a shot of silicon spray into the nipple and then actuating the switch with your fingers repeatedly. That gets them moving and sealing again. You may need to spray again in a year, but they will work. Hi Jim, Thanks for that. I did try that as I had seen your post about doing this several years ago. So far, no luck. I did pull one off of one of my parts cars. I sprayed that with silicone as well. That one did not do the trick either. This was off of a pretty toasty car though. I will try to find yet one more to see if this is actually the problem. Is there a way to test the switch in or out of the car? Bill Edited June 3, 2023 by Riviera63 (see edit history) Link to comment Share on other sites More sharing options...
telriv Posted June 3, 2023 Share Posted June 3, 2023 Bill, A lot of those vacuum switches come apart. Although by the picture that does not look like it. The grease that makes them slide solidifies & becomes hard. Sorta like the power seat pieces. IF it will come apart clean out ALL the old hard grease & re lube with my favorite grease which also acts as a sealer. Tom T. Link to comment Share on other sites More sharing options...
gungeey Posted June 4, 2023 Share Posted June 4, 2023 what happens when you bypass the switch (I think it's a modulator valve?) altogether with a double barbed vacuum hose connector? Link to comment Share on other sites More sharing options...
Zimm63 Posted June 4, 2023 Share Posted June 4, 2023 Test it with a hand vacuum pump to be sure its the problem. NOS ones do show up on ebay occasionally. Search using the part number, and save the search. Not an immediate solution, but thats how I was able to replace mine. I did keep the old one to see if I could take it apart. Its in my get to it stack, behind the fairly constant stream of broken stuff that has to be dealt with when you have multiple old cars and motorcycles. 1 Link to comment Share on other sites More sharing options...
Riviera63 Posted June 4, 2023 Author Share Posted June 4, 2023 31 minutes ago, Zimm63 said: Test it with a hand vacuum pump to be sure its the problem. NOS ones do show up on ebay occasionally. Search using the part number, and save the search. Not an immediate solution, but thats how I was able to replace mine. I did keep the old one to see if I could take it apart. Its in my get to it stack, behind the fairly constant stream of broken stuff that has to be dealt with when you have multiple old cars and motorcycles. I took your advice and tested the switch with a hand pump. It appears that the switch is not the problem. At least according to my test. Hooked it up to an extra vacuum actuator that I have and when vacuum is applied the actuator pulls in as it should and holds. I will try bypassing the switch as gungeey suggested to see what happens as well. Bill Link to comment Share on other sites More sharing options...
Chasander Posted June 5, 2023 Share Posted June 5, 2023 (edited) Old air products list a couple of these switches for corvette and ford. Looks close Edited June 5, 2023 by Chasander (see edit history) Link to comment Share on other sites More sharing options...
1965rivgs Posted June 5, 2023 Share Posted June 5, 2023 Bill, In the picture you are applying vacuum both directly to the actuator and through the switch, if the plunger on the switch is depressed. If you are attempting to only test the switch, use a vacuum gauge, not an actuator, and run your hose from the hand pump to the switch and lastly the vacuum gauge. Tom Link to comment Share on other sites More sharing options...
Riviera63 Posted June 5, 2023 Author Share Posted June 5, 2023 When the Cool lever is in the "off" position the plunger is depressed not allowing vacuum to go through the switch. From what I understand when the Cool lever is in the "on" position it releases the plunger and allows vacuum to flow through the switch to the blue vacuum line which in turn "T's" up with the blue line from switch # 3 and goes to the actuator on the firewall via a black line. The green line from switch #3 also goes to the actuator. Vacuum has to be applied to both ports on the actuator to pull the door open so that air flows to the AC vents. My first set up which wasn't exactly true to this routing. I redid it with the correct routing as in the car minus switch #3. The same result. Vacuum flowed through the switch and in turn to the actuator. I also did the way you suggested. The switch allowed vacuum through and registered on the gauge. What all of this tells me is that switch # 1 is good. I now believe I need to test switch # 3 to see if it is the culprit. Bill Link to comment Share on other sites More sharing options...
1965rivgs Posted June 5, 2023 Share Posted June 5, 2023 8 hours ago, Riviera63 said: When the Cool lever is in the "off" position the plunger is depressed not allowing vacuum to go through the switch. From what I understand when the Cool lever is in the "on" position it releases the plunger and allows vacuum to flow through the switch to the blue vacuum line which in turn "T's" up with the blue line from switch # 3 and goes to the actuator on the firewall via a black line. The green line from switch #3 also goes to the actuator. Vacuum has to be applied to both ports on the actuator to pull the door open so that air flows to the AC vents. My first set up which wasn't exactly true to this routing. I redid it with the correct routing as in the car minus switch #3. The same result. Vacuum flowed through the switch and in turn to the actuator. I also did the way you suggested. The switch allowed vacuum through and registered on the gauge. What all of this tells me is that switch # 1 is good. I now believe I need to test switch # 3 to see if it is the culprit. Bill Yes, testing each component with a gauge is best. The actuators are notorious for bypassing internally and inconsistent operation. I have returned quite a few new repros. The actuators are 80/20 dual stage. They partially retract with vacuum applied to only one port and fully retract when vacuum is applied to both ports. The key is vacuum needs to be applied to the correct port first before being applied to the second port for full retraction. Tom Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now