Terminator X Air Conditioning Help Tech Article 91-93 Models

Anderson Ford Motorsport Tech

Terminator X (AF-AFM-937F) Air Conditioning wire write up using factory wiring for 91-93 Mustang.

The following tech article refers to the Holley Terminator X and X Max for Fox Body Mustang air conditioning systems that are performed at the Anderson Ford Motorsport Installation Facility. We have essentially two versions with diagrams to view. The following information covers general steps and procedures done with the factory wiring that is incorporated into the Holley system. If your vehicle was not equipped with air conditioning from the factory some of these steps may be different. Wiring colors confirmed for 91-93 Fox Mustang. For 86-90 model years refer to the other tech article.

Note*

We now offer the Fathead Garage A/C Wiring Kit specifically for 86-93 Fox Body Mustangs for a brand new wiring solution. This removes the need for the factory air conditioning wiring.

One thing we’ve noticed with the Holley Terminator X system for Fox Body Mustangs is that with all the new wiring harnesses it can scare the average consumer who may not be too tech savvy thinking it’s a monumental task to perform. The reality is that the Holley system is about 90% plug and play. The 10% is what seems to be intimidating. 1- The factory wiring to gain functionality of the gauge cluster and 2- Factory air conditioning seem to be the main culprits of this. We are going to start with the assumption you have all of your factory engine and EEC harness removed from the vehicle and show how straight forward the process is for installing the air conditioning wiring back into the car.

The key things to keep an eye on are the connectors for the factory air conditioning relay, accumulator and ground connectors. Most of these connections can be unraveled from the factory harness. You will need to cut/de-pin some of these wires as they ran through factory connectors that are no longer used. You are able to gain a considerable length of wire if you de-pin the wires needed. You can leave the compressor plugged in and remove the connector that is close to the power steering pump.

The best way to summarize what will be done is knowing what wires stay in the engine bay and what goes into the interior of the vehicle. There will be three total wires that will be going back into the interior of the vehicle. For 91-93 vehicles the purple wire coming from the green factory connector will plug back into the factory interior harness. We found de-pinning the connector and removing the remaining unnecessary wires makes it cleaner.

The next wire that goes back into the interior will be the orange with yellow stripe wire. This wire comes from the WOT shut off relay. This wire will make a connection to the Holley wiring harness.

The last wire to return to the interior will be the black with yellow stripe wire. This wire comes from the accumulator pressure switch plug. This wire will also make a connection to the Holley harness.

For the Holley wires we use the preconfigured input/output wiring shown below.

Orange/Yellow Stripe to B10 (Gray w/ Black stripe)

Black/Yellow Stripe to A12 (White w/ Blue stripe)

We usually start putting things into place before finalizing connections so we can verify length needed that way if wires need to be extended everything is still in a serviceable spot. We’ve found that most applications will not need to lengthen any wires going back into the interior especially if you de-pinned the wires from the factory connections. Wires that go to the WOT shut off relay can actually be shortened if you relocate the relay over to the drive side of the vehicle.

The black w/ yellow stripe wire can be cut down and shortened to length you need (from compressor harness to ground harness).

The factory ground connection will need to remain intact with the plug for the compressor. There will additional grounds connected to this joint. You may use these as additional ground sources or can cut them off and wrap them safely away from each other. Again you may cut and shorten the connections if needed just keep the plugs intact.

The last wire connection will be the solid red wire from the WOT shut off relay. This needs to be connected to a 12v + connection. A switched constant source is what we have been running with no issues. We usually attach an eyelet and post to the starter solenoid.

We use matching Holley loom to wrap all wires for a clean look. Generally the 3/8” split loom will be large enough to tuck the wires but not too big to be an eye sore. Holley part number 573-104.

We finalize the loom on the AC harness and make our final connections. We generally use the factory ground locations unless they are no longer suitable. Make sure the metal is clean of rust and debris for a solid ground connection. Again the Holley has these inputs/outputs setup out of the box to use in the software. Just be sure to go into the software verify that everything is pinned in the correct location. You may have to adjust the IAC kick when the a/c is turned on to best suit your setup.

Just to reiterate what is needed from the factory harness to run air conditioning with the Holley below (91-93 models):

-Purple wire (comes from accumulator pressure switch to factory green interior connector)

-Black w/ yellow stripe (comes from accumulator pressure switch to Holley inputs/outputs harness)

-Pink w/ blue stripe (comes from accumulator pressure switch to WOT shut off relay)

-Accumulator Pressure Switch connector

-Red wire (comes from WOT shut off relay)

-Black w/ yellow stripe (comes from WOT shut off relay to compressor harness)

-Orange w/ yellow stripe (comes from WOT shut off relay to Holley inputs/outputs harness)

-Wide Open Throttle Shut Off Relay

-Compressor harness (comes from ac compressor)

-Black w/ white stripe (Factory ground, comes from compressor harness)

*Technical Note about this information

The harness wire colors shown in this article are from a 91-93 Fox Body Mustang harness. Due to the many changes Ford did throughout the 86-93 model years some of the colors may not be the same. However, you can pull up wiring diagrams online to confirm the color from an earlier model year if your colored wires are different on the WOT shut off relay or accumulator plug.

Diagram 1