News: Putting FUN and FRIENDLINESS, FIRST into owning and learning about AMC small bodied cars, primarily Eagles, Spirits and Concords as well as vehicles built in AMC's Mexican subsidiary, VAM.

The AMC Eaglepedia can now be accessed using the buttons found below  This is a comprehensive ever growing archive of information, tips, diagrams, manuals, etc. for the AMC Eagle and other small bodied AMC cars. 

Also a button is now available for our Face Book Group page.


Welcome to the AMC Eagles Nest.  A new site under "old" management -- so welcome to your new home for everything related to AMC Eagles, Spirits and Concords along with opportunities to interact with other AMC'ers.  This site will soon be evolving to look different than it has and we will be incorporating new features we hope you will find useful, entertaining and expand your AMC horizons.

You can now promote your topics at your favorite social media site by clicking on the appropriate icon (top upper right of the page) while viewing the topic you wish to promote.


  • March 28, 2024, 12:17:45 PM

Login with username, password and session length

Author Topic: How could I hook up the A/C from scratch after my wires and vacuum was trashed?  (Read 11681 times)

0 Members and 1 Guest are viewing this topic.

Offline madmax4x4

  • Eagle
  • **
  • Posts: 60
  • Thumbs Up 1
How could I hook up the A/C from scratch after my wires and vacuum was trashed? Got a motor put in and carb conversion all my vacuum and a lot of wires have been removed by the mechanic. Problem now is no vac for heater or 4wd controls and I don't know how to hook my ac back up. Compressor still in with two wires coming from it. Anyone know how I could hook it up again or if I could put a fuse on it and run a switch to turn it on and off? Or how much power can go to it from where? Battery or other?  :banghead: 

Offline madmax4x4

  • Eagle
  • **
  • Posts: 60
  • Thumbs Up 1
I got the ac hose I was missing now. Not show in photo yet. I have not put it on.

« Last Edit: July 04, 2014, 02:22:35 PM by madmax4x4 »

Offline BenM

  • AMC Eagles Den Addicted
  • ********
  • Posts: 1512
  • Thumbs Up 74
  • Pittsburgh, PA
Vacuum-wise, a line goes from the back of the manifold to what appears to be a missing vacuum canister and in to the HVAC head unit. That switches the heater valve. It's pretty simple.

Electrically, the power is fed from the head unit, through the A/C thermostat on the heater box, across to the low pressure switch and to the clutch, which is grounded on the other wire. It's a gray wire with a black tracer.
NSS#47184

1987 AMC Eagle Sedan -- 1976 Pacer Coupe -- 1968 Pontiac Tempest Custom S -- 1940 Mercury (& a 2002 Jetta Turbodiesel, 5 spd., the Wife's Daily Driver)

Offline madmax4x4

  • Eagle
  • **
  • Posts: 60
  • Thumbs Up 1
Vacuum-wise, a line goes from the back of the manifold to what appears to be a missing vacuum canister and in to the HVAC head unit. That switches the heater valve. It's pretty simple.

Electrically, the power is fed from the head unit, through the A/C thermostat on the heater box, across to the low pressure switch and to the clutch, which is grounded on the other wire. It's a gray wire with a black tracer.
Thanks for the reply. I think I see what needs to be done to the heater I got another vacuum canister just need the ball now. But I'm lost on the ac part. Both wires I see coming from the ac clutch or compressor are connected to each other at the end with a single port plug. I see with the dash out how to ac is turned on in the control unit but don't know where the other stuff is. Basically I don't know where to put the wire from the compressor now that the mechanic cut a lot of the stuff under the hood out.     

Offline madmax4x4

  • Eagle
  • **
  • Posts: 60
  • Thumbs Up 1
I picked up the green vacuum hose from a concord to go to the heater. I only had a black and a green vacuum hose going to the back of the heater/ac controls. But it looks like I have another port on it with no hose at all.

Offline BenM

  • AMC Eagles Den Addicted
  • ********
  • Posts: 1512
  • Thumbs Up 74
  • Pittsburgh, PA
Sorry, it must ground through the housing. The paired wires have a diode in them. That keeps the magnetic clutch from frying the car's electronics when it disengages. It's a big magnetic coil just like the ignition coil and can create a big feedback spice when the field collapses.

Anyway, power to that wire engages the clutch.

Here's the diagram

Over on the driver's side, down low by the subframe is a small A/C hose with a sight glass on it. On or near there is a switch that turns off the clutch if the high side pressure is too low. This is necessary because the oil is in the coolant, and with low pressure your compressor will burn out quickly.

Run a wire from the magnetic clutch to one side of this switch.

Run another wire from the other side into the cabin near the glove box.

When you remove the glove box you should see the A/C thermostat box on the left side. It has a bulb that goes into the heater box on a thin tube, like a mechanical temperature gauge. The thermostat is controlled by a cable and cycles the clutch to adjust the temperature of the evaporator. It helps to keep the evaporator core from freezing up.

If the heater wiring is not messed up you should be able to find the gray/black wire in the harness in the engine compartment, otherwise you'll have to wire straight to the A/C thermostat.
NSS#47184

1987 AMC Eagle Sedan -- 1976 Pacer Coupe -- 1968 Pontiac Tempest Custom S -- 1940 Mercury (& a 2002 Jetta Turbodiesel, 5 spd., the Wife's Daily Driver)

Offline madmax4x4

  • Eagle
  • **
  • Posts: 60
  • Thumbs Up 1
I don't see the diode not sure if it has one still. Still having trouble figuring out what to do because I'm no good at reading the wiring diagram. I do see the switch by the sight glass and it's still hooked up and a have a vacuum canister from the junkyard now but I don't have the ball shaped vacuum thing. Not sure if I need it or not.

Offline eaglefreek

  • Moderators
  • AMC Eagles Den Addicted
  • *****
  • Posts: 4011
  • Thumbs Up 209
Where are you located? Maybe there is someone near you that has the wiring in tact. Did you get the 4x4 vacuum lines figured out? I may have some of, if not all of the lines in my shed.
1986 AMC Eagle Wagon 4.2L/4.0L head, AW4,NP242, Chrysler 8.25" rear.
1981 AMC Eagle Wagon As Seen On TV  Lost In Transmission


 

"I know he'd be a poorer man, if he never saw an eagle fly,
Rocky mountain high"  John Denver
Click for Fayetteville,TN Forecast" border="0" height="100" width="150

Offline madmax4x4

  • Eagle
  • **
  • Posts: 60
  • Thumbs Up 1
I'm in New Orleans La. As of now Im not worried about the 4x4 but I have a new motor that I haven't broke in because is sucks not have ac in the south. :rotfl:
I'm going to do the hose clamp trick and lock in the front and try to get the shift on the fly switch from a later eagle or do a brake cable mod.

It's an 83AMC SX/4. I have everything but the dash out right now I have been redoing the inside just need carpet right now but don't want to order it until I figure out the cabin water leaks I posted about in another thread.. Put the seat back in a few days ago to drive it around a bit. Been parked almost a year after the new motor has been put in.

It too hot  :banghead: outside already

Offline madmax4x4

  • Eagle
  • **
  • Posts: 60
  • Thumbs Up 1
I had the wires and vac hoses removed to make it simpler but the didn't do a very good job. Now the hoses are all gone and I still have a ton of wires left behind   :(

I've been looking at this
http://amceaglesden.com/guide/Group_13_Heater_--_Air_Conditioning
 because one of the problems I have is water coming from the cabin fresh air port (the push pull knob) but can't find a diagram of it.
« Last Edit: May 02, 2015, 06:47:08 PM by madmax4x4 »

Offline madmax4x4

  • Eagle
  • **
  • Posts: 60
  • Thumbs Up 1
So this is where I'm at with it all. Pic from the bottom of the climate control. Green vac line go's to the heater hose switch. Black vac line go's out to the vacuum ball canister (don't have it yet but will get on)

Then the third spot has a place for another line but I don't no what?

Nothing is shown for that spot in the diagram.  http://amceaglesden.com/guide/images/d/df/13heater009.jpg



Green vac line from control will be hooked directly to this.


Black vac line from control runs directly to the vacuum canister ball that was here?


I see from pics of the ball it has another spot for a vac line in it also. Where does that go? Is that the line that should go to the back of the manifold as mentioned before?
« Last Edit: May 03, 2015, 02:32:31 PM by madmax4x4 »

Offline madmax4x4

  • Eagle
  • **
  • Posts: 60
  • Thumbs Up 1
As far as the AC I have the switch with the grey wires with black tracer going back into the cabin.


Then that leads to a switch or something in the dash

Then the the ac control


Really everything looks normal just don't know what to hook this to now.
 
« Last Edit: May 03, 2015, 03:19:57 PM by madmax4x4 »

Offline mo.eagles

  • Eagle DL
  • ***
  • Posts: 241
  • Thumbs Up 13
  In the harness ( in your pic its the one running down the shock tower ) there should be a gray wire with a black stripe . That is the wire you need to plug the two compressor wires into. That wire goes to the pressure switch and then into the switch under the dash.  So when you switch on A/C power goes from dash switch to the pressure switch . If your system is low on coolant  then that switch will not allow compressor to run .  The vacuum hoses are correct . There are only two plugged into that switch.
'85 wagon Limited   tilt wheel , cruise control
power seats ,windows and locks
rear window washer /wiper 
tach and gauge package
A/C
 '85 wagon   power windows and locks
rear window washer/wiper
factory tow package
A/C

Offline eaglefreek

  • Moderators
  • AMC Eagles Den Addicted
  • *****
  • Posts: 4011
  • Thumbs Up 209
I think that third spot is just a post to give the connector a tight fit.  As far as the wire to the compressor, mo. stated, there is a wire that comes out of the harness in that area. Check down by your alternator, it might be hanging out down there.
1986 AMC Eagle Wagon 4.2L/4.0L head, AW4,NP242, Chrysler 8.25" rear.
1981 AMC Eagle Wagon As Seen On TV  Lost In Transmission


 

"I know he'd be a poorer man, if he never saw an eagle fly,
Rocky mountain high"  John Denver
Click for Fayetteville,TN Forecast" border="0" height="100" width="150

Offline madmax4x4

  • Eagle
  • **
  • Posts: 60
  • Thumbs Up 1
I think that third spot is just a post to give the connector a tight fit.  As far as the wire to the compressor, mo. stated, there is a wire that comes out of the harness in that area. Check down by your alternator, it might be hanging out down there.

Those wires are gone after the new motor was put in so I have to run a new wire from this the wherever it is suppose to go. But I can't figure that part out. Like in the pic the two wires from the compressor (ground, diode, and power in) come together as one. So that the wire I need to run to one side of the grey with black tracer wire on the switch by the sight glass?
« Last Edit: May 04, 2015, 02:55:47 PM by madmax4x4 »

Offline madmax4x4

  • Eagle
  • **
  • Posts: 60
  • Thumbs Up 1
 I guess my question is if a run a wire from this connector that gives power to the compressor where would I run it too?

Offline madmax4x4

  • Eagle
  • **
  • Posts: 60
  • Thumbs Up 1
Sorry, it must ground through the housing. The paired wires have a diode in them. That keeps the magnetic clutch from frying the car's electronics when it disengages. It's a big magnetic coil just like the ignition coil and can create a big feedback spice when the field collapses.

Anyway, power to that wire engages the clutch.

Here's the diagram

Over on the driver's side, down low by the subframe is a small A/C hose with a sight glass on it. On or near there is a switch that turns off the clutch if the high side pressure is too low. This is necessary because the oil is in the coolant, and with low pressure your compressor will burn out quickly.

Run a wire from the magnetic clutch to one side of this switch.

Run another wire from the other side into the cabin near the glove box.

When you remove the glove box you should see the A/C thermostat box on the left side. It has a bulb that goes into the heater box on a thin tube, like a mechanical temperature gauge. The thermostat is controlled by a cable and cycles the clutch to adjust the temperature of the evaporator. It helps to keep the evaporator core from freezing up.

If the heater wiring is not messed up you should be able to find the gray/black wire in the harness in the engine compartment, otherwise you'll have to wire straight to the A/C thermostat.

Sorry I think I understand know and you answered my question a year ago  :occasion14:

So all I need to do is run a wire from the compressor wire to one side of that switch to the sight glass?
Looks like that's also what is said here in this thread.  http://forums.amceaglesden.com/index.php?topic=43466.0

Run a wire from this connector
 

To one side, any side of this wire on the switch


Is that right?
« Last Edit: May 04, 2015, 02:44:51 PM by madmax4x4 »

Offline mo.eagles

  • Eagle DL
  • ***
  • Posts: 241
  • Thumbs Up 13
 Not either wire ,but the wire that goes to that plug in your hand . One of those wires on the pressure switch will be power from your dash switch when in A/C position .  Unplug the pressure switch ,turn on the A/C and with a test light or VOM check for power at those two wires. If you have voltage at one of the two ,which you should, then wire your compressor plug to the other wire. (the wire with no power )  But I would first open that wire harness that runs down your shock tower and see if the mech did not just push the wire you need into the bundle and wrap a whole roll of electrical tape around it . ( The way it looks in your pics)  Because I see no need to cut off a wire that's only about 6" long . I think (as a mech) he just put it in that plastic harness wrap.
'85 wagon Limited   tilt wheel , cruise control
power seats ,windows and locks
rear window washer /wiper 
tach and gauge package
A/C
 '85 wagon   power windows and locks
rear window washer/wiper
factory tow package
A/C

Offline mo.eagles

  • Eagle DL
  • ***
  • Posts: 241
  • Thumbs Up 13
There should have been a smaller harness coming out of that big harness on your shock tower going to the alternator . That is where the grey wire with black tracer should be.
'85 wagon Limited   tilt wheel , cruise control
power seats ,windows and locks
rear window washer /wiper 
tach and gauge package
A/C
 '85 wagon   power windows and locks
rear window washer/wiper
factory tow package
A/C

Offline madmax4x4

  • Eagle
  • **
  • Posts: 60
  • Thumbs Up 1
Thanks I'm going to open up the harness and look for it in the morning.

Offline madmax4x4

  • Eagle
  • **
  • Posts: 60
  • Thumbs Up 1
Got it working thanks everyone for the help  :hello2: :hello2: :occasion14:

Offline mo.eagles

  • Eagle DL
  • ***
  • Posts: 241
  • Thumbs Up 13
  I knew you could do it !!   :hello2:    Did you use R12 or 134?
'85 wagon Limited   tilt wheel , cruise control
power seats ,windows and locks
rear window washer /wiper 
tach and gauge package
A/C
 '85 wagon   power windows and locks
rear window washer/wiper
factory tow package
A/C

Offline madmax4x4

  • Eagle
  • **
  • Posts: 60
  • Thumbs Up 1
One can of r134a to fill it to the green on the gauge. Not sure if it leaks yet. It blows cold but I'm not sur if it's blowing cold as it should. I'm going to order a new dryer and maybe have to old oil pulled out and new oil put in. At least I got the thing to come on  ;D

 

SMF spam blocked by CleanTalk