ETR valve

[ImperialLeBaron1969]

Im a bit confused regarding the ETR valve solenoid. I cant find the electric connection for that on my rv2 compressor. The brown hangs loose and I cant find where to connect it. In the shop manuel, theres no pic of the connector.

Autotemp systems use a ETR valve instead of a EPR valve in the compressors for manual AC.

If I buy a remanufactured compressor, its there 2 versions, one for manual AC and one for autotemp? I have tried to do some research but cant find an answer. There is a tread there on the forum too, but I cant find information on the connector

 

[CBODY67]

You might find it on the big a/c line, at the break in the lines, where the EPR valve would be, but with an electrical connection blade on the backside of that line nut, IIRC. Like an inline screen with a blade connector on it.

Just some thoughts,
CBODY67

 

[ImperialLeBaron1969]

You might find it on the big a/c line, at the break in the lines, where the EPR valve would be, but with an electrical connection blade on the backside of that line nut, IIRC. Like an inline screen with a blade connector on it.

Just some thoughts,
CBODY67

Could the ETR be missing? Or at least the connector. Cant find it.

 

[Davea Lux]

The ETR valve is normally in the same place as the EPR valve on non ATC systems. Yours would appear to have been removed. It would usually have a 12v lead to the valve, I see a 12 volt connector in the photo on the right side of the compressor but that might be to the compressor clutch assembly. Factory wiring usually would have one lead to the compressor clutch and one to the ETC valve. Check to see if lead to the compressor clutch has the second wire that has been taped over.

Dave

 

[ImperialLeBaron1969]

The ETR valve is normally in the same place as the EPR valve on non ATC systems. Yours would appear to have been removed. It would usually have a 12v lead to the valve, I see a 12 volt connector in the photo on the right side of the compressor but that might be to the compressor clutch assembly. Factory wiring usually would have one lead to the compressor clutch and one to the ETC valve. Check to see if lead to the compressor clutch has the second wire that has been taped over.

Dave

Thanks! I have both leads and the compressor runs, of i connect the clutch lead. But i have that disconnected because there is no pressure in the system

 

[Davea Lux]

Thanks! I have both leads and the compressor runs, of i connect the clutch lead. But i have that disconnected because there is no pressure in the system

The ETR valve was unreliable and that part has been obsolete for 30 years or more. A lot of them were removed as they usually stuck shut and rendered the A/C inoperative. As a fix, some systems had a EPR valve installed to prevent compressor hammering, the A/C would work that way, but that fix disabled the thermostat control and left the user with manual air.

Dave

 

[ImperialLeBaron1969]

The ETR valve was unreliable and that part has been obsolete for 30 years or more. A lot of them were removed as they usually stuck shut and rendered the A/C inoperative. As a fix, some systems had a EPR valve installed to prevent compressor hammering, the A/C would work that way, but that fix disabled the thermostat control and left the user with manual air.

Dave

I understand
I guess that its not good for the compressor when the valve is removed and left open.
The best way today is, according to a rebuilder, to remove the valve and use a cycling clutch instead. There is a sensor in the evaporator that was connected to the ETR switch. This could be used to connect to the clutch with a closing relay.

 

[ImperialLeBaron1969]

I managed to find the connector to the ETR valve/solenoid thanks to the excellent documentation @vdk2010 did! The pic here is from his documentation. Its a tiny connector, almost hidden when the compressor is mounted in the car. I had to remove the air cleaner to find it. When I tested the soleniod, I found that it still moves. My old system still hold some pressure on R12, but it doesnt cool.

 

[Moseman]

I understand
I guess that its not good for the compressor when the valve is removed and left open.
The best way today is, according to a rebuilder, to remove the valve and use a cycling clutch instead. There is a sensor in the evaporator that was connected to the ETR switch. This could be used to connect to the clutch with a closing relay.

Okay, In my complete rebuild of my 72 Imperial, I am elbows deep in the A/C rebuild. Do you know of any wiring diagrams or discussion on the fix that you mention? I have a NOS EPR valve, but a sketchy ETR valve. Is there a simple test to see if the ETR valve works? I should look at the manual. I do have an Autotemp II tester (actually 2)
Or, just go the way you stated, insert a EPR valve, and wire into the clutch circuit?

 

[Moseman]

The ETR valve was unreliable and that part has been obsolete for 30 years or more. A lot of them were removed as they usually stuck shut and rendered the A/C inoperative. As a fix, some systems had a EPR valve installed to prevent compressor hammering, the A/C would work that way, but that fix disabled the thermostat control and left the user with manual air.

Dave

Dave, I replied to Imperial LeBaron 69 with this. Do you have any recommendations?
Okay, In my complete rebuild of my 72 Imperial, I am elbows deep in the A/C rebuild. Do you know of any wiring diagrams or discussion on the fix that you mention? I have a NOS EPR valve, but a sketchy ETR valve. Is there a simple test to see if the ETR valve works? I should look at the manual. I do have an Autotemp II tester (actually 2)
Or, just go the way you stated, insert a EPR valve, and wire into the clutch circuit?

 

[ImperialLeBaron1969]

Dave, I replied to Imperial LeBaron 69 with this. Do you have any recommendations?
Okay, In my complete rebuild of my 72 Imperial, I am elbows deep in the A/C rebuild. Do you know of any wiring diagrams or discussion on the fix that you mention? I have a NOS EPR valve, but a sketchy ETR valve. Is there a simple test to see if the ETR valve works? I should look at the manual. I do have an Autotemp II tester (actually 2)
Or, just go the way you stated, insert a EPR valve, and wire into the clutch circuit?

I have the older Autotemp I, you have the never Autotemp II. The RV2 compresor that Imperial uses has an ETR valve, manual AC (non autotemp cards) uses an EPR valve. I think that if you rebuild the compressor you remove the valve and let the clutch cykle. The EPR/ETR valve is used to control the temperature in the system and prevent the evaporator to freeze and that can be done by letting the clutch cyklde. The EPR valve cannot be used in a Autotemp system according to the shop manual for 1969.

Your autotemp II is explained here:
I also recommend that you get the 1972 shop manual that explains the system.

Your Autotemp II system uses a power servo located in the engine compratment. This servo usually need to be rebulid:
Chrysler/Imperial Climate Control Servo | eBay

Check for leaks and get yourself a vacuum gauge!

/Gustav

 

[Davea Lux]

Dave, I replied to Imperial LeBaron 69 with this. Do you have any recommendations?
Okay, In my complete rebuild of my 72 Imperial, I am elbows deep in the A/C rebuild. Do you know of any wiring diagrams or discussion on the fix that you mention? I have a NOS EPR valve, but a sketchy ETR valve. Is there a simple test to see if the ETR valve works? I should look at the manual. I do have an Autotemp II tester (actually 2)
Or, just go the way you stated, insert a EPR valve, and wire into the clutch circuit?

The main reason to install the EPR valve in place of the ETR valve was to protect the compressor from slugging liquid refrigerant and beating itself to death. As noted, this disabled all of the thermostatic controls. You can install a cycling switch wired to the clutch that measures temperature on the suction side of the evaporator. A drop in temperature will cut out the compressor clutch and allow liquid refrigerant to clear the line. This is another way to protect the compressor, but it still leaves the factory thermostatic controls disabled. Check the ETR valve by checking to see if it is open at normal room temperature. If it is closed, it is junk. Run a continuity test from the terminal on the ETC valve to the case on the ETR valve, you should get a completed circuit. In theory, if you have a completed circuit, the valve should work assuming it is not stuck. As noted, these valves were a POS and prone to sticking either open or shut.

Dave

 

[Moseman]

The main reason to install the EPR valve in place of the ETR valve was to protect the compressor from slugging liquid refrigerant and beating itself to death. As noted, this disabled all of the thermostatic controls. You can install a cycling switch wired to the clutch that measures temperature on the suction side of the evaporator. A drop in temperature will cut out the compressor clutch and allow liquid refrigerant to clear the line. This is another way to protect the compressor, but it still leaves the factory thermostatic controls disabled. Check the ETR valve by checking to see if it is open at normal room temperature. If it is closed, it is junk. Run a continuity test from the terminal on the ETC valve to the case on the ETR valve, you should get a completed circuit. In theory, if you have a completed circuit, the valve should work assuming it is not stuck. As noted, these valves were a POS and prone to sticking either open or shut.

Dave

Thanks, I will take a picture of the valve and do what you said. Too bad, I sent the compressor, brackets and intake pipe to Original Air to be rebuilt. They said it was junk and could not be rebuilt. I asked to have my all the other parts other than the compressor sent back to me. Well, they tore it all apart, and sent back only part of the stuff I wanted. The valve is with the suction pipe, thankfully, I hope it survived.

 

[Davea Lux]

Thanks, I will take a picture of the valve and do what you said. Too bad, I sent the compressor, brackets and intake pipe to Original Air to be rebuilt. They said it was junk and could not be rebuilt. I asked to have my all the other parts other than the compressor sent back to me. Well, they tore it all apart, and sent back only part of the stuff I wanted. The valve is with the suction pipe, thankfully, I hope it survived.

There are usually rebuilt, used and core compressor units for sale on E-bay. U-pull it is another source. O'Reily's still shows a listing for rebuilt units but I do not know the availability of their units.

Dave

 

[Moseman]

There are usually rebuilt, used and core compressor units for sale on E-bay. U-pull it is another source. O'Reily's still shows a listing for rebuilt units but I do not know the availability of their units.

Dave

Dave, I am the proud owner of about 25 70's Chryslers. I have about 3-4 RV2 cores, or useable units. But, I cannot find a total RV2 rebuild kits. Original Air lost the inside or rear bracket for the 72. I robbed a 73, but they are different from 72 to 73 Imperials. I got used brackets from Murray Park. I have two RV2's that I will look at to see if they are clean and useable. One, a rebuilt off of Evil Bay, the outher out of a 78 NYer. I tooke a unit off of a 73 Charger which had a bad front seal. So, the need for a rebuild kit!

Thanks,

 

[Moseman]

There are usually rebuilt, used and core compressor units for sale on E-bay. U-pull it is another source. O'Reily's still shows a listing for rebuilt units but I do not know the availability of their units.

Dave

Dave, I have attached two photos of my ETR Valve. This is what I received back from Original Air. Not sure if it is all there?

 

[Davea Lux]

Looks to be complete to me.

Dave

 

[Moseman]

Looks to be complete to me.

Dave

Thanks, I now need to figure out how that works! That little filter/strainer thingie has a hole in it. So, the spring heats up and pushes on the black rubber housing and closes off the intake? Just guessing.

 

[ImperialLeBaron1969]

I think its a pressure regulator. Opens if pressure to high or low