Auto temp 2 :(

[Giovanni1776]

Hello

Proud owner of a 76 NYer .. the air doesn’t work.. no air vent, no windshield defrost, no ac .. I can press the dash knobs as much as I want .. nothing engage ..

Any tips ?

Thank you guys

 

[MoPar~Man]

I'm guessing your car uses R12 or R22 ?

Up here in Canada, we can't buy DIY actual freon. There's stuff called "RedTek" that is an HC-based (propane I think) refrigerant, I've used it successfully on my 300M's (replacing R134).

You'd have to make sure you can get your compressor clutch to activate when the engine is running. If there's no refrigerant in the system then a sensor might prevent the clutch from activating so you'd have to jumper the clutch manually to come on.

One way or another, if your compressor does run then all you need are the right fittings or adapters for your ports and a can or 2 of RedTek. Canada tire and Princess auto sells them, but who knows if the stuff will still be available next year.

 

[Davea Lux]

Hello

Proud owner of a 76 NYer .. the air doesn’t work.. no air vent, no windshield defrost, no ac .. I can press the dash knobs as much as I want .. nothing engage ..

Any tips ?

Thank you guys

View attachment 621622

If you have nothing, no movement of the air doors, no A/C clutch engagement etc. You may have a bad actuator or a bad vacuum switch on the auto temp control. Check the vacuum line to the auto temp switch to see if vacuum is getting that far. If you have vacuum there without any leakage from the control, next check to see if there is vacuum at the auto temp actuator. Suggest you down load a copy of the FSM at www.mymopar.com. These systems are a major PIA to diagnose and the FSM gives detailed instructions on trouble shooting and repair. A lot of the parts for these systems are obsolete and difficult to find, so good luck.

Eave

 

[Giovanni1776]

If you have nothing, no movement of the air doors, no A/C clutch engagement etc. You may have a bad actuator or a bad vacuum switch on the auto temp control. Check the vacuum line to the auto temp switch to see if vacuum is getting that far. If you have vacuum there without any leakage from the control, next check to see if there is vacuum at the auto temp actuator. Suggest you down load a copy of the FSM at www.mymopar.com. These systems are a major PIA to diagnose and the FSM gives detailed instructions on trouble shooting and repair. A lot of the parts for these systems are obsolete and difficult to find, so good luck.

Eave

Thank you very much sir

 

[ImperialLeBaron1969]

A vacuum gauge is very useful. Vacuum leaks drops the system vacuum and the master switch needs vacuum to turn on. This is a very helpful video:

The autotemp II uses a power servo located in the engine compartment. It can go bad. Buy A new one here: Chrysler/Imperial Climate Control Servo | eBay
The system wont kick in if its cold outside, the engine temperature has to reach 80 F before its does. There are 2 vacuum hoses at the bottom of the servo unit that control this delay. The vacum hoses can be removed from the servo and connected together. By doing this, Autotemp will go on instantly even if its cold.

 

[Giovanni1776]

A vacuum gauge is very useful. Vacuum leaks drops the system vacuum and the master switch needs vacuum to turn on. This is a very helpful video:

The autotemp II uses a power servo located in the engine compartment. It can go bad. Buy A new one here: Chrysler/Imperial Climate Control Servo | eBay
The system wont kick in if its cold outside, the engine temperature has to reach 80 F before its does. There are 2 vacuum hoses at the bottom of the servo unit that control this delay. The vacum hoses can be removed from the servo and connected together. By doing this, Autotemp will go on instantly even if its cold.

Thank you very much

But for 600 hundreds dollars .. I will stay with my non-working auto temp for now ..

 

[ImperialLeBaron1969]

Yes its expensive, BUT there could be other problems than the servo, vacuum lines for example.

I have a Autotemp I. Someones had mixad up alla the vacuum lines at the power servo. What a mess, but now its working again.

 

[Giovanni1776]

Super

 

[thethee]

A vacuum gauge is very useful. Vacuum leaks drops the system vacuum and the master switch needs vacuum to turn on. This is a very helpful video:

The autotemp II uses a power servo located in the engine compartment. It can go bad. Buy A new one here: Chrysler/Imperial Climate Control Servo | eBay
The system wont kick in if its cold outside, the engine temperature has to reach 80 F before its does. There are 2 vacuum hoses at the bottom of the servo unit that control this delay. The vacum hoses can be removed from the servo and connected together. By doing this, Autotemp will go on instantly even if its cold.

A 1976 NY should have the AutoTemp II 2.0 system which does NOT use the power servo unit in the engine bay. Instead, the servo unit will be mounted on top of the heater box under the dash cover. These units will NOT interchange.

 

[ImperialLeBaron1969]

A 1976 NY should have the AutoTemp II 2.0 system which does NOT use the power servo unit in the engine bay. Instead, the servo unit will be mounted on top of the heater box under the dash cover. These units will NOT interchange.

Thanks, I didnt know that. Was 1973 the last year for Autotemp II, or later?

 

[thethee]

Thanks, I didnt know that. Was 1973 the last year for Autotemp II, or later?

I believe so, a lot of systems changed between fuselage and formal years.

 

[ImperialLeBaron1969]

Very interesting. I love the old ACC systems. They are ingenious, but of course they have their drawbacks.

 

[thethee]

Hello

Proud owner of a 76 NYer .. the air doesn’t work.. no air vent, no windshield defrost, no ac .. I can press the dash knobs as much as I want .. nothing engage ..

Any tips ?

Thank you guys

View attachment 621622

The easiest check to perform is to see if the vacuum canister in the engine bay doesn't have any leaks and the vacuum lines are correctly connected. The violet line should be main vacuum supply to the unit IIRC.

Second cause could be the cold engine lockout of the water valve has failed, preventing all function of the fan. Remove the orange and light green vacuum lines from the side of the water valve. Connect those together and see if the fan comes on.

Third, check the fan itself, see if it has power and if it runs when you jumper it.

There are many more possible issues but pretty much all of those involve removing the dash pad and that is not a fun job.

 

[CS43FI]

Hello

I'm repairing 1978 ATC II and I borrow Your thread.

I found #1 Check Valve defective on my system. I did the test prochedure of 1978 FSM page 24-119 - symptoms were just as described.

Part # 2820 880.

While sourcing for original one, I'm interested in substituting the valve with replica made of generic parts. Do You know the internal schematic of the valve?
I tested the presumably working valve and came up with following schematic. Ports 1-2 and 3-4 are connected and air flows opposite to arrow.

Thanks.

 

[75LandYacht]

This is all very interesting. As my Auto temp stooped work in my 77 last summer. I hear hissing from under passenger side dash. Time to investigate…

 

[commando1]

Hello

I'm repairing 1978 ATC II and I borrow Your thread.

I found #1 Check Valve defective on my system. I did the test prochedure of 1978 FSM page 24-119 - symptoms were just as described.

Part # 2820 880.

While sourcing for original one, I'm interested in substituting the valve with replica made of generic parts. Do You know the internal schematic of the valve?
I tested the presumably working valve and came up with following schematic. Ports 1-2 and 3-4 are connected and air flows opposite to arrow.

Thanks.

View attachment 642209

View attachment 642208

Nice investigating work.
Keep it up.

 

[3175375]

Hello

I'm repairing 1978 ATC II and I borrow Your thread.

I found #1 Check Valve defective on my system. I did the test prochedure of 1978 FSM page 24-119 - symptoms were just as described.

Part # 2820 880.

While sourcing for original one, I'm interested in substituting the valve with replica made of generic parts. Do You know the internal schematic of the valve?
I tested the presumably working valve and came up with following schematic. Ports 1-2 and 3-4 are connected and air flows opposite to arrow.

Thanks.

View attachment 642209

View attachment 642208

I am unsure of its function. However, I could probably figure it out if I saw the schematic. Where do connections 2, 3 and 4 go?

 

[CS43FI]

Nice investigating work.
Keep it up.

Thanks. I share my observations in case someone finds something helpful out of them. If there's any detail I can share that helps others, please let me know.

I answer to my own question - Yes. The valve's internal function is as drawn. I managed to disassemble the faulty valve with pipe cutter. There's a diaphragm, which could be removed with separate center pin. The plastic "seat" of the rubber valve had crack in it. Some superglue+baking soda fixed it. Finished with some sanding and vacuum test before case went back together with hot glue. Leak test under water with pressure. This was a tedious job and took about an hour. The result was not perfect but it worked on the system so far. Ugly it is, but fortunately it is hidden inside dash.

Picture 1: Disassembled valve. Rubber holding center pin still in place because I only figured out later that it can be removed.

Picture 2: Valves in place. #1 (upper) is the repaired one.

I found another problem. Defrost-Bleed vacuum actuator (right over throttle pedal) was leaking when vacuum applied on shaft side chamber (Defrost mode). This seems to be a common problem with actuators. Therefore blower did not come on at all on LO/HI DEF since there was insufficient vacuum for Master Switch. On the bench test the actuator rod seal seems to seal itself when extended to full travel but this was not achieved when on place.

Picture 3: Fixed actuator. added zip-tie to aid rubber sealing. washers to bring the unit down allowing full extension and sealing of the chamber. No more vacuum leaks.

Bonus Picture 4: Familiar view for all who have fixed ATC. I had to connect hand vacuum pump to vacuum tank during testing. Engine cannot be turned on since the garage door must stay closed because there's -20 °C / -4 F temperature outside. In this picture You can see two white wires which are used as a jumper on Master Switch leads. This is an emergency option to force blower on in case some problems occur on vacuum system. You see, defrost and heat are absolutely necessary where I live.

 

[3175375]

Thanks. I share my observations in case someone finds something helpful out of them. If there's any detail I can share that helps others, please let me know.

I answer to my own question - Yes. The valve's internal function is as drawn. I managed to disassemble the faulty valve with pipe cutter. There's a diaphragm, which could be removed with separate center pin. The plastic "seat" of the rubber valve had crack in it. Some superglue+baking soda fixed it. Finished with some sanding and vacuum test before case went back together with hot glue. Leak test under water with pressure. This was a tedious job and took about an hour. The result was not perfect but it worked on the system so far. Ugly it is, but fortunately it is hidden inside dash.

Picture 1: Disassembled valve. Rubber holding center pin still in place because I only figured out later that it can be removed.
View attachment 642581

Picture 2: Valves in place. #1 (upper) is the repaired one.
View attachment 642582

I found another problem. Defrost-Bleed vacuum actuator (right over throttle pedal) was leaking when vacuum applied on shaft side chamber (Defrost mode). This seems to be a common problem with actuators. Therefore blower did not come on at all on LP/HI DEF since there was insufficient vacuum for Master Switch. On the bench test the actuator rod seal seems to seal itself when extended to full travel but this was not achieved when on place.

Picture 3: Fixed actuator. added zip-tie to aid rubber sealing. washers to bring the unit down allowing arm extend fully and seal the chamber. No more vacuum leaks.
View attachment 642584

Bonus Picture 4: Familiar view for all who have fixed ATC. I had to connect hand vacuum pump to vacuum tank during testing. Engine cannot be turned on since the garage door must stay closed because there's -20 °C / -4 F temperature outside. In this picture You can see two white wires which are used as a jumper on Master Switch leads. This is an emergency option to force blower on in case some problems occur on vacuum system. You see, defrost and heat are absolutely necessary where I live.
View attachment 642586

Good work!

 

[CS43FI]

I am unsure of its function. However, I could probably figure it out if I saw the schematic. Where do connections 2, 3 and 4 go?

Hi.

Vacuum schematic for Your information. Could be found in New Yorker Online.
All modes illustrated in FSM.

Page_24-097.jpg