C3 Vette Registry - The Best Resource on the Net for C3 Vettes! C3 Vette
Forums -> C3 Cooling and Heating Systems
Not Logged In! Login or Register!  Users Online: 22 / Help 
Features  Find C3 Parts on ebay in only 2 or 3 clicks!  | Add YOUR C3 to the Registry

Supporting Vendors
Mid America Motorworks
Volunteer Vette Products
VetteBookStore.com
CorvetteClothing.com
Bair's Corvettes

C3 of the Month
None Current
Enter Yours Today!
Online C3 Show
13
C3s are Registered

Vanity Plates
1COOLC3
hunt4cleanair
Featured Links

Buy Now
Chevrolet Corvette: 1968 thru 1982, All V8 models (Haynes Manuals) (Paperback)
Chevrolet Corvette: 1968 thru 1982, All V8 models (Haynes Manuals) (Paperback)


Chevrolet Corvette Restoration Guide
Chevrolet Corvette Restoration Guide


GM Corvette 1963-82 (Chilton's Total Car Care Repair Manuals) (Paperback)
GM Corvette 1963-82 (Chilton's Total Car Care Repair Manuals) (Paperback)


How To Rebuild Corvette Rolling Chassis 1963-1982
How To Rebuild Corvette Rolling Chassis 1963-1982



| Hide Signatures and Profile Pics

 New Topic New Topic Post Reply Reply New Poll New Poll Search     Search Page [1]  
6/10/08 1:26pm - Original Message: 'THERMOSTAT CUT OFF SWITCH'
79FOREVER
Standard Member
- Send Private Message


METAIRIE, LA - USA

Vette(s):
1979 BLACK COUPE

Joined: 6/7/2007
Posts: 144

OK HERE IT GOES.  WHAT IS THE FUNCTION OF THE THERMOSTAT CUT OFF SWITCH ON MY 1979 CORVETTE?  IT LOOKS PRETTY BAD, PLASTIC BOTTOM FEEL OFF, RE-GLUED IT.  I RUN THE SYSTEM; JUST TO KEEP IT WORKING, DO NOT USE IT A LOT.

 

HOW DO YOU TELL IF IT IS EVEN WORKING?  ORIGINAL SYSTEM NEEDS FREON, LOW, COOLS VERY POORLY, ALWAYS DID.   LOOKING FOR FREON?  COMPRESSOR CUTS OFF AND ON, ALWAYS THOUGH IT WAS DUE TO LOW FREON.

 

THERE WAS SOME TYPE OF OLD BLACK INSTALLATION TAPE OVER THE COPPER LEAD WHICH IS HELD IN PLACE BY TWO CLAMPS TO THE LOWER LINE GOING INTO THE EVAPRATOR BOX.  MY HEATER HOSE LINES RUN RIGHT AGAINST IT.  ENGINE BAY IS NOT ALL ORIGINAL, LOT OF STUFF REMOVED.  HEATER LINES NEED TO BE AGAINST FENDER WELL, KEEPING THEM AWAY FROM THE MANIFOLD.

 

IF WORKING, SHOULD I SETUP SOME KIND OF HEAT BARRIER OVER THE COOPER LEAD?  LAST NIGHT I PUT SOME PIPE INSTALLATION OVER IT W/ SOME Y TIES, CANNOT STAY THAT WAY, HEATER LINES GET TO HOT.  IF THAT SENSOR IS SENSING COLD, I AM GUESSING I NEED A HEAT BARRIER.

 

JOE

JOSEPH.DEWEY@LANEWO.ANG.AF.MIL

 Reply Reply  Quote Reply w/Quote
 
Support C3VR!
Suport our advertisers
6/11/08 12:03pm - Reply: 'THERMOSTAT CUT OFF SWITCH'
dwright Gold Member
Gold Member
Moderator
- Send Private Message


Victor, NY - USA

Vette(s):
2004 Commemorative Edition Coupe, Auto w/HUD. 13K miles in 2015. Sold 1982 Red Coupe

Joined: 7/12/2004
Posts: 6756
Joe,
Judging by the response, I would say not too many of us are familiar with your set-up.
 
Do you think the PO cobbled something up to make the AC work?


____________________________________
http://www.c3vr.com/member_uploads/6301_6400/6346/Copy-of-IMG_267720156754455r.jpg

Save the Wave!
Support the National Corvette Museum   
 Reply Reply  Quote Reply w/Quote
6/11/08 12:32pm - Reply: 'THERMOSTAT CUT OFF SWITCH'
79FOREVER
Standard Member
- Send Private Message


METAIRIE, LA - USA

Vette(s):
1979 BLACK COUPE

Joined: 6/7/2007
Posts: 144

ECKLERS PART # 27118, IN ASSEMBLY BOOK, SHOWS A PIC OF IT, BUT NOT INFO.  ACDELCO AIR CONDITIONING THERMOSTAT CUT-OFF SWITCH. 



____________________________________
Joe Dewey             
joseph.d.dewey.mil@mail.mil
joe.dewey@yahoo.com


Click for larger view



 Reply Reply  Quote Reply w/Quote
6/11/08 1:17pm - Reply: 'THERMOSTAT CUT OFF SWITCH'
DaveM Lifetime Member
Lifetime Member
- Send Private Message


Flanders, NJ - USA

Vette(s):
1982 Black, ZZ4, Hooker Side Pipes, 3.55 Rear, Rebuilt & upgraded 700R4, All new suspension, brakes, & new Charcoal interior.

Joined: 1/27/2004
Posts: 2530
Send a PM to "my7T1" (Terry) he has an AC shop and is the go to man for AC help.
Dave


____________________________________
 

Lifetime Member #116
Dave's '82


   
 Reply Reply  Quote Reply w/Quote
6/11/08 1:26pm - Reply: 'THERMOSTAT CUT OFF SWITCH'
79FOREVER
Standard Member
- Send Private Message


METAIRIE, LA - USA

Vette(s):
1979 BLACK COUPE

Joined: 6/7/2007
Posts: 144

Thank you Dave, done, hopefully he will know.  Part is for 78 / 79 in Ecklers.



____________________________________
Joe Dewey             
joseph.d.dewey.mil@mail.mil
joe.dewey@yahoo.com


Click for larger view



 Reply Reply  Quote Reply w/Quote
6/11/08 7:17pm - Reply: 'THERMOSTAT CUT OFF SWITCH'
my7t1 Lifetime Member
Lifetime Member
- Send Private Message


Dorr, MI - USA

Vette(s):
71 Colonnade Hardtop Coupe Torch Red with black interior originally L48 built to push around 360hp

Joined: 8/21/2002
Posts: 2580
PM sent.

____________________________________

Click on images for Before and After pics!
 Reply Reply  Quote Reply w/Quote
6/12/08 8:12pm - Reply: 'THERMOSTAT CUT OFF SWITCH'
79FOREVER
Standard Member
- Send Private Message


METAIRIE, LA - USA

Vette(s):
1979 BLACK COUPE

Joined: 6/7/2007
Posts: 144

Hey Terry,

Put everything back together.  Compressor will not run unless that switch is plugged in.  Would be very hard to check the voltage w/ it plugged in.  System cycles shortly and after running a while the compressor stays on all the time while running in my garage.  Lower line gets very cold and sweats a lot.  I will try and fine some R12 and re-service the system one day.  Any further advice is welcomed and thanks again for all your help I do appreciate it.

 

Joe

 

79FOREVER2008-06-12 17:14:46

____________________________________
Joe Dewey             
joseph.d.dewey.mil@mail.mil
joe.dewey@yahoo.com


Click for larger view



 Reply Reply  Quote Reply w/Quote
6/12/08 8:52pm - Reply: 'THERMOSTAT CUT OFF SWITCH'
kstyer Lifetime Member
Lifetime Member
Moderator
- Send Private Message


CUYAHOGA FALLS, OH - USA

Vette(s):
1975 C3 Red, T-Tops, Black Interior. All I need is time and money! Getting there!

Joined: 12/2/2003
Posts: 6410
Your car has an orifice tube and accumulator system.  If you are looking at the sensor in the low pressure line with two wires that is the low pressure cutoff switch.   If the pressure drops too low, the compressor kicks off.  This also controls the compressor cycling.  It is not a temp sensor, just pressure.   Keep in mind that cycling refrigerant will maintain a temperature relative to pressure, so it does act like a temp switch, but it is not.
 
Therfore, if the compressor is cycling, the switch is working.  You may need to check the freon level, but it sounds like the system is working fairly normally.    If the system is full, but not cooling properly you may have some contamination in the system.  This could just be air.  If that's the case you would need to have it connected to a vacuum pump, and evacuate the system and refill it.


____________________________________
On the "Tail of the Dragon"
(some day, no strike that, October 2008 it turned red, still in progress!)

(click either image to see a bigger version)
 Reply Reply  Quote Reply w/Quote
6/12/08 9:21pm - Reply: 'THERMOSTAT CUT OFF SWITCH'
my7t1 Lifetime Member
Lifetime Member
- Send Private Message


Dorr, MI - USA

Vette(s):
71 Colonnade Hardtop Coupe Torch Red with black interior originally L48 built to push around 360hp

Joined: 8/21/2002
Posts: 2580
Like Ken says Joe, if the compressor is cycling, the switch is working. If your suction line is getting that cold, are you getting cold air in the cabin? If the compressor isn't short cycling, and that line is cold, you may not need a charge.

____________________________________

Click on images for Before and After pics!
 Reply Reply  Quote Reply w/Quote
6/12/08 9:55pm - Reply: 'THERMOSTAT CUT OFF SWITCH'
79FOREVER
Standard Member
- Send Private Message


METAIRIE, LA - USA

Vette(s):
1979 BLACK COUPE

Joined: 6/7/2007
Posts: 144

Ken, the switch has to be a temp. sensor, it is clamped to the outside of the low pressure line going into the bottom of the evaporator core box.  I may  not be understanding correctly what you are trying to tell me.  Agree about contamination, it may have some, have never done anything to the system when I restored the car in the early 90's.  Had Freon added a couple of times that is all.

 

Terry, yes, getting cold air in the cab.  It stopped short cycling after running it a while.  Is that normal or do I have to be driving the car w/ air going across the condenser?

79FOREVER2008-06-12 18:56:29

____________________________________
Joe Dewey             
joseph.d.dewey.mil@mail.mil
joe.dewey@yahoo.com


Click for larger view



 Reply Reply  Quote Reply w/Quote
6/12/08 10:00pm - Reply: 'THERMOSTAT CUT OFF SWITCH'
my7t1 Lifetime Member
Lifetime Member
- Send Private Message


Dorr, MI - USA

Vette(s):
71 Colonnade Hardtop Coupe Torch Red with black interior originally L48 built to push around 360hp

Joined: 8/21/2002
Posts: 2580

The hotter the abbient temp. the longer the compressor will run witout cycling off. When your moving, increasing the RPM's, and bringing air across your condenser, it will get colder.



____________________________________

Click on images for Before and After pics!
 Reply Reply  Quote Reply w/Quote
6/13/08 12:23pm - Reply: 'THERMOSTAT CUT OFF SWITCH'
79FOREVER
Standard Member
- Send Private Message


METAIRIE, LA - USA

Vette(s):
1979 BLACK COUPE

Joined: 6/7/2007
Posts: 144
Ok, Terry the next time I am dirving I will listen to see if the compressor is cycling after running a while.  I think the system is working pretty good, may just need some R12 as discussed.  It was a hot day yesterday and I was in my garage running, high 80's easy.

____________________________________
Joe Dewey             
joseph.d.dewey.mil@mail.mil
joe.dewey@yahoo.com


Click for larger view



 Reply Reply  Quote Reply w/Quote
6/13/08 1:33pm - Reply: 'THERMOSTAT CUT OFF SWITCH'
79FOREVER
Standard Member
- Send Private Message


METAIRIE, LA - USA

Vette(s):
1979 BLACK COUPE

Joined: 6/7/2007
Posts: 144
Loaded a pic of my money hole.

____________________________________
Joe Dewey             
joseph.d.dewey.mil@mail.mil
joe.dewey@yahoo.com


Click for larger view



 Reply Reply  Quote Reply w/Quote
6/13/08 6:14pm - Reply: 'THERMOSTAT CUT OFF SWITCH'
kstyer Lifetime Member
Lifetime Member
Moderator
- Send Private Message


CUYAHOGA FALLS, OH - USA

Vette(s):
1975 C3 Red, T-Tops, Black Interior. All I need is time and money! Getting there!

Joined: 12/2/2003
Posts: 6410
If it has a tube attached and the tube goes into the evaporator housing or attaches to the low pressure hose, there is a sensor bulb attached to the low pressure side.  The tube has a small sensor bulb.  When heated or cooled gas in the bulb expandes and travels through the tube to make the switch open or close.  So it has the exact same effect.  These were usually used on slightly older cars.  I would not have expected it on a 79.  But again, the function is the same, and the results are the same. kstyer2008-06-13 15:14:54

____________________________________
On the "Tail of the Dragon"
(some day, no strike that, October 2008 it turned red, still in progress!)

(click either image to see a bigger version)
 Reply Reply  Quote Reply w/Quote
6/13/08 8:09pm - Reply: 'THERMOSTAT CUT OFF SWITCH'
my7t1 Lifetime Member
Lifetime Member
- Send Private Message


Dorr, MI - USA

Vette(s):
71 Colonnade Hardtop Coupe Torch Red with black interior originally L48 built to push around 360hp

Joined: 8/21/2002
Posts: 2580
Sweeeeet Ride Joe. Hope ya can keep her coolThumbs%20Up

____________________________________

Click on images for Before and After pics!
 Reply Reply  Quote Reply w/Quote
6/14/08 11:43am - Reply: 'THERMOSTAT CUT OFF SWITCH'
79FOREVER
Standard Member
- Send Private Message


METAIRIE, LA - USA

Vette(s):
1979 BLACK COUPE

Joined: 6/7/2007
Posts: 144
Ken,
 
Maybe, there is a copper or brass metal lead coming off the switch and is clamped to the outside of the lower line, it was not going into the box.
 
Thanks for the input.
 
Thanks Terry.


____________________________________
Joe Dewey             
joseph.d.dewey.mil@mail.mil
joe.dewey@yahoo.com


Click for larger view



 Reply Reply  Quote Reply w/Quote
7/12/08 8:10pm - Reply: 'THERMOSTAT CUT OFF SWITCH'
Brown78
Former Member
- Send Private Message


Ft.Lauderdale, FL - USA

Vette(s):
78 coupe, Dk Brown, ZZ4 385 hp fast burn, steeroid rack/pinion, Keisler 5 speed. Built to run with C5 and C6. on the highway. Can't beat them. But they can't lose me in there mirrors. LOL I built it to enjoy. So far I've tripped through 15 States.

Joined: 6/21/2008
Posts: 31
are you talking about the water shutoff switch with a plastic button on a spring inside the car??  That is connect to the water shutoff  down by the heater hoses on the passenger side??

____________________________________
Steve

Click on any image for larger view!
 Reply Reply  Quote Reply w/Quote
7/13/08 10:48am - Reply: 'THERMOSTAT CUT OFF SWITCH'
79FOREVER
Standard Member
- Send Private Message


METAIRIE, LA - USA

Vette(s):
1979 BLACK COUPE

Joined: 6/7/2007
Posts: 144

No, something different.  I don't have what you are describing at all on my 79.



____________________________________
Joe Dewey             
joseph.d.dewey.mil@mail.mil
joe.dewey@yahoo.com


Click for larger view



 Reply Reply  Quote Reply w/Quote
 New Topic New Topic Post Reply Reply New Poll New Poll Search     Search Page [1]  
 Forums -> C3 Cooling and Heating Systems
(Moderator: Adam Wartell, Norsky, Adams' Apple)
 

 
Official C3 Vette Registry Community:
Home | Forums | Email | Who's Online | Clubs | Events | Member Stats

Other Official C3 Vette Registry Areas:
Members | Research | Shop | My Account | About C3VR
 

Corvette is a registered trademark of the General Motors Corporation(GM) & Chevrolet Motor Division. Vette Registries, LLC is responsible for all site content (except for member submitted content or where otherwise noted) and does not claim or imply that Chevrolet or GM is responsible for Official C3 Vette Registry content. Vette Registries, LLC is independent from GM and is not affiliated with, sponsored or supported by GM.  Copyright/trademark/sales mark infringements are not intended, or implied and are in fact used to support GM, Chevrolet and Corvette

Official C3 Vette Registry content is Copyright 2001-2017, Vette Registries, LLC. Content may not be reused without written consent. All Rights Reserved. NS

Corvette (Vette) Model Years on this site: 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 30