'79 A/C Evaporator- See Pics
03-04-2006, 03:03 PM
#1
Drifting
Thread Starter
'79 A/C Evaporator- See Pics
I am trying to make sense of this switch that comes off of the Evaporator. If you look in the pic you can see the thin metal line looped to itself. This was all tucked in that black plato substance. What is this and should it be connected to the switch at the hole in the bad pic #2?
If it sould be what is a good way to reconnect it?
I got a new evaporator and am not sure if this was bubba'd somehow.
If it sould be what is a good way to reconnect it?
I got a new evaporator and am not sure if this was bubba'd somehow.
03-04-2006, 03:13 PM
#3
Le Mans Master
I belive that those 2 go together. If so, they cannot be reconnected-you have to get a new switch. The wire is actually a line full of gas similar to a mechanical temperature gauge. As the evaporator tries to freeze, the switch turns off the compressor to keep it from freezing, as the temperature rises the compressor is allowed to come back on. Cycle continues.
I thought 79 had a pressure cycling switch like most GM cars of the late 70s and forward. It would be screwed onto a port on the accumulator. Maybe Vettes started that in 80? Serves the same function, but uses pressure instead of temperature.
I thought 79 had a pressure cycling switch like most GM cars of the late 70s and forward. It would be screwed onto a port on the accumulator. Maybe Vettes started that in 80? Serves the same function, but uses pressure instead of temperature.
03-04-2006, 08:15 PM
#6
Melting Slicks
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Isn't that line clamped to the evap inlet actually a thin tube, a capillary line? And that switch, whatever it is it's evidence that bubba was there. If these two were connected together my guess is it's a thermal switch actuated when the capillary line sees a set temp. One thing is for sure, it's not original.
Last edited by shafrs3; 03-04-2006 at 08:32 PM.
03-04-2006, 10:14 PM
#7
Melting Slicks
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St. Jude Donor '05-'06,'11,'13-'14,'16,'18,'19
That is the thermostat that cycles the comp to keep the coil temp above freezing so condensate does not freeze on the coil and block the airflow. I am not sure what year they stooped using the thermostat and went to the low-pressure switch to cycle the comp. The small tube is the cap tube and it should be attached to the thermostat, it cannot be reattached. It was charged with a gas to sense temp change. I have attached a photo of my 77 its not a very good photo but if you look close you can see the thermostat attached with a bracket near the bottom of the evap coil box. Does your wiring harness have a plug for the thermostat?
Neal
Neal
03-05-2006, 08:07 AM
#9
Melting Slicks
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Oops, I stand corrected. Page 57 item S in Dr. Rebuild catalog shows switch.
http://docrebuild.com/dr-r-web/ac-switch.pdf
http://docrebuild.com/dr-r-web/ac-switch.pdf
Last edited by shafrs3; 03-05-2006 at 06:31 PM.
03-05-2006, 08:43 AM
#10
Le Mans Master
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Looks like it isn't a bubba add. Seems like it is actually a Tempreture switch used to detect the temp of the evap by wrapping the capilary line around the evaporator line, aparently shutting off the compressor as the evaporator approaches freezing, Interesting. I thought at first it was charged by AC system gas but its completely independant.
