Non A/C to A/C Swap 88-94

[7thdarkangel]

I have been seeing a lot of questions about doing this, so I'm making this thread to hopefully answer most of them.

You will need a donor/parts tuck or access to a pick and pull.

Donor Parts list:

-Ac box and wiring
-The ac selector (controller that goes under the stock radio)
-The hard AC lines
-Compressor and idler – you will need the bracket
-Pulley set – AC pulleys are wide than the non ac pulleys (If your alternator has the narrow pulley you can either pull just the pulley, grab the whole alternator, or get a new one for AC)
-Duct work behind the dash
-Gage bezel with the vent on the left side.
-The snap in vent on the passenger side near the door.
-Center bezel with vents (if you don’t already have one)
-Trim piece under the steering wheel without the vent levers. (AC doesn’t have them)
-Glove box cubby (unfortunately they are smaller)
-Condenser mounts – Upper and lower

Bag and tag all nuts and bolt that you take off. It will help tremendously when you are putting thing s back together.


While I was pulling things out I thought it was a good opportunity to add the passenger side courtesy light switch in the dash. My truck did not come with it, so it made sense to add what I wanted with the dash out.


All the other components you can buy new if you would like to. I would however recommend a new evap core and heater core before you put the new box in. The whole dash has to come out again in order to replace them later.


My swap is mostly done so there are some pictures I just can’t get but I will do what I can to explain or clarify anything.


When you go to remove the AC box from the donor you will notice 3 wires (Red, Light Green, Light Grey) from the box harness go through the bulk head into the engine bay. You can either swap the whole harness into your truck, or snip the three wire and run the through a grommet or separate bulkhead to the engine bay. If you snip them be sure to save the connectors that attach to the compressor and pressure switch so you can build the circuit again later

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Once you have all the parts, you’re going to start by removing the dash. Here is a video that explains that process:

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[7thdarkangel]

Once the dash is out you will need to remove the non ac box. Clamp off the heater core line and disconnect them. Remove the overflow res. There are studs that go thru the firewall with nuts on them, those are for the box. There is also a bolt on the inside of the cab at the top of the box that needs to come out. And lastly unplug it from the dash harness.

Here is a video that shows the mount points/studs pretty well:

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You also have to remove the manual recirculation vent on the driver side. Once removed you need to tape it off or you will have a constant draft. I used gorilla tape.

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Now that the old stuff is out, you will need to drill two holes for the new AC lines. My truck had dimples in the fire wall to locate where they are supposed to be. If yours doesn’t you will need to make a template off of the AC box, measure a few times and drill the holes.

At this point, all the old stuff should be out. Take a look at the back side of the dash and replace the duct work with the ones from the donor. Clean them first, you don’t want all those nasties slapping you in the face when you turn the air on. While you’re cleaning those, clean the ac box as well for the same reason.

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Now would be a good time to replace the evap and heater core if you choose to. If you chose to swap the whole bay harness do so now (if you did kudos to you). If you chose to snip the wires now is the time to drill for a grommet or bulkhead. Once your box is ready, you can go ahead and install it. All your studs and bolt go in the same place. The wiring harness is a direct plug in to where your old one was disconnected. If you snipped the three wires, connect and run a few feet of wire out into the engine bay.

Before you start to put the dash back in connect the AC controller and test to make sure the motors on the box are functioning correctly. Those that snipped the harness will need to run 12v to the red wire they snipped. Once confirmed you can reinstall your dash. Be sure to install the donor gauge bezel with ducting, passenger side vent and center vents.

Ill drop this here in case you need it.

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[7thdarkangel]

You are now most of the way done.

All that is left is the engine bay. All of my comments are based off the one piece stamped steel bracket. You can start with swapping over the pulleys and removing the idler. This part is pretty straight forward as you are just bolting thing on. The compressor and idler can now be installed. The grill will have to come off the truck to install the condenser. Install the dryer up on the firewall and connect it to the evap. With those components installed you can now finish running your lines. The use of new o rings and orifice tube is recommended.

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All that is left is the wiring. If you swapped over the harness all you have to do is plug in the pressure switch and compressor. If you snipped the wires, here is the diagram to hook it all back up on the engine bay side.

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If I missed anything let me know and Ill do what I can to add the info

 

[Bardo]

This is awesome. I'm bringing my truck home this weekend and this will be the 2nd (first thing is fixing cab corners and rockers) thing on my to do list.

 

[7thdarkangel]

Here is a little bit more info.

This is the one I used. I pulled the box and controller together. It does not need the ecu to work.

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Here are the connectors under the dash that you ac/non ac box plug into. The multi pin is what your non ac box will be plugged into. The single connector with the brown wire is what will give your controller power. When you go to remove your old box nothing will be plugged into the single connector with the brown wire.

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