78 New Yorker. climate control switches & Window electrical issues

[emeryd17]

There's a click almost like a relay in the dash when I press the buttons for the vent, heat, etc. but nothing happens. I have no air coming through, so my guess is there's just no power going to anything.
do I have to tear apart the dash and check everything over? if so, how would I get in there?
the A/C compressor and everything else is in good condition and the car runs and drives very well.

the only issues I'm having is the entire HVAC system, and the windows don't roll down, I have power to the switch but no power out of the switch, maybe about 1-2V. I took the switch apart and cleaned everything really well, do I try and find new old stock replacements?

I tested all the fuses also and they were good.

any input or tips is highly appreciated, Thanks - Emery

 

[CS43FI]

Hi. I'm not an expert on anything. Do You have manual A/C or Auto Temp II (Does it have blower speed control switch or not)? You should check if A/C vacuum line is connected in engine compartment. Hard 1/8 line coming out of the middle of the firewall. If all fuses are also ok, the next step is to go inside the dash. When inside dash, following steps hignly depend on which system You have. You mentioned that compressor is good - does it turn and make cold? This could be the situation even though interior unit is not working properly.

If You don't own Factory Service Manual, You can check 1977 version online. It should be 95% equivalent to 1978.
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What kind of window switches do You have? Basic or Brougham/Imperial style? First one might be easier to find if necessary. Imperial style switch has window lock-button and all signals pass through driver switch panel. I experienced the same issue as You have and it went away after I washed all four switch panels in ultrasonic cleaner. The system could be tested by jumper wires to isolate switch problems.

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[emeryd17]

Hi. I'm not an expert on anything. Do You have manual A/C or Auto Temp II (Does it have blower speed control switch or not)? You should check if A/C vacuum line is connected in engine compartment. Hard 1/8 line coming out of the middle of the firewall. If all fuses are also ok, the next step is to go inside the dash. When inside dash, following steps hignly depend on which system You have. You mentioned that compressor is good - does it turn and make cold? This could be the situation even though interior unit is not working properly.

If You don't own Factory Service Manual, You can check 1977 version online. It should be 95% equivalent to 1978.
Page_24-002.jpg

What kind of window switches do You have? Basic or Brougham/Imperial style? First one might be easier to find if necessary. Imperial style switch has window lock-button and all signals pass through driver switch panel. I experienced the same issue as You have and it went away after I washed all four switch panels in ultrasonic cleaner. The system could be tested by jumper wires to isolate switch problems.

Page_08-194.jpg

Mine is the Auto Temp II, all fuses are ok. I haven't been able to get any air at all coming through the vents, what I meant by "the compressor looks good" is that it turns freely and visually looks good, I'm not sure how I would test it to see unless my fans and everything start working. could I put power to the compressor to see if the clutch does anything?
I've heard that manual A/C is better, how could I convert to that?

And with the windows, they are the brougham style switches, I had them apart and cleaned and there's still not enough voltage coming through. I'll probably just have to get them ultrasonic cleaned.
I want to try and get one or the other working right now, its getting pretty hot out and I have no air and no windows, haha

thanks for the help, I'm going to mess around with it some more today.

 

[CS43FI]

Ok, then I would primarily recommend going through ATC diagnostics in service manual. There might be only simple bug to disable the whole system - such as vacuum leak. There's a master vacuum switch for the blower motor. If it is not getting vacuum, there's no blower. Vacuum also goes through cold cutoff valve on heater hose (engine compartment). It's easy to check and bypass to isolate one possible fault. ATC requires some perseverance to deal with.

The compressor clutch can be checked by applying +12V to the only electric connector that goes inside the clutch assembly. If You are unsure if the system is charged with refrigerant, either measure continuity on refrigerant pressure switch (0 ohm = pressure) or press lightly on any refrigerant valve stem. The major issue here is of course the blower. ATC - if working properly - is usable even without refrigerant.

I can't recommend the conversion at this point, but there sure are people that will do it right away. I also don't judge either one better. I would think the conversion as a last resort if ATC has multiple confirmed and expensive malfunctions. The conversion sure is a major overhaul - more experienced people may help with that.

I see Your problem. One would really like either one or both AC/Windows to work on hot weather...

 

[emeryd17]

Ok, then I would primarily recommend going through ATC diagnostics in service manual. There might be only simple bug to disable the whole system - such as vacuum leak. There's a master vacuum switch for the blower motor. If it is not getting vacuum, there's no blower. Vacuum also goes through cold cutoff valve on heater hose (engine compartment). It's easy to check and bypass to isolate one possible fault. ATC requires some perseverance to deal with.

The compressor clutch can be checked by applying +12V to the only electric connector that goes inside the clutch assembly. If You are unsure if the system is charged with refrigerant, either measure continuity on refrigerant pressure switch (0 ohm = pressure) or press lightly on any refrigerant valve stem. The major issue here is of course the blower. ATC - if working properly - is usable even without refrigerant.

I can't recommend the conversion at this point, but there sure are people that will do it right away. I also don't judge either one better. I would think the conversion as a last resort if ATC has multiple confirmed and expensive malfunctions. The conversion sure is a major overhaul - more experienced people may help with that.

I see Your problem. One would really like either one or both AC/Windows to work on hot weather...

Thanks, I'll give the diagnostics a try, I'll try to take pictures where needed and come back here with all the info I gather.