87/88 TC EEC-IV into XR

What you need: 87-88 TC computer (5 speed is code LA3) big VAM 9/16 inch drill bit with 1/2" chuck drill an ACT sensor for 87-88 Turbo Coupe (pepboys $21.99) ACT sensor socket Tap (I don't remember the size exactly I believe 3/8 NPT... whatever size the ACT sensor is) a junkyard or parts car EEC4 harness from any vehicle, cut from the car with at least 3 inches of wire left on each pin) set of jeweller's screwdrivers 1" socket, deep teflon tape some 18-16 guage wire and a means to connect them (crimping/soldering/etc...) needle nosed pliers voltmeter

First, you must modify the lower intake to accept an ACT sensor. So, remove the lower intake from the car. On the firewall side of the intake, you will see an allen plug (located between the guage sender and the fan switch). Remove it. Mount your intake in a vice or in a set of sturdy human hands. Get out the drill and molest that hole until it is 9/16 inch diameter. Then tap the hole for the sensor and install the sensor.

Reinstall the lower intake ONLY. You need clearance for the wiring.

Get your spare EEC harness. See that red thing that surrounds all of those pins? Pry it out using your jeweller's screwdrivers. You can now extract individual pins from the harness. To remove a pin, grab the wire and pull gently while twisting it. It will come free. For an easy install into an XR, pull out three wires and have them handy.

Get in your car and remove the EEC. Pull out the harness so that you have sufficient clearance, and remove the black protective cover. Pry out the red pin retainer as before. Now you must be careful because you can conceivably yank all of the wires from your harness. You wouldn't want that!

Identify Pin #1. It is at one of the corners of the harness and has a yellow wire. Pins 2 and 3 should be free, 4 should be taken. Identify pin 1 correctly or you will be very sorry. FIRST, locate pin 43. Grab the wire with your needle nosed pliers, and pry it out of the harness in the previous manner. Locate pin 27, it should be empty. Push the pin you just removed into pin 27 till it clicks. Next, locate pin 25 and pull it out. Locate pin 43 and insert the pin you just pulled. Locate and pull pin 32. Insert into pin 31. Locate and pull pin 35. Insert into pin 33.

OK, thats all for pin movement. Now you get to ADD pins. The LA3 has 8 more circuits than a PF3. It is only practical (or necessary) on a non cruise controlled XR to add 3 of these 8 circuits. You may be able to add yet another 2 (VSS and VSSDIF) on an XR with cruise, but Antonius' doesn't have cruise.

Grab one of the spare wires you pulled from the junk harness. Locate pin 2 of your harness and insert the spare wire. Insert two more spare wires at pins 24 and 25.

Remove the lower side of the driver's dash. Pull the plug at the brake switch and probe the two contacts. One will show +12 and the other will be zero. Splice a wire to the side that reads zero, run it to the EEC harness, and connect it to the wire that you put in pin 2.

Get your ACT sensor socket. Splice a wire to the colored lead and run it through the firewall to the EEC harness. How you run it is up to you. I ran the wire through the grommet near the brake booster. Connect this wire to the one you inserted into pin 25. Connect the other lead of the ACT socket to ground. You may want to splice this to a signal return wire (black/white stripe from any sensor) to keep the computer circuits isolated from others. That's what I did, but I don't see why it would really matter. Connect the wire that you inserted into pin 24 to ground or signal return. That puts your LA3 in premium fuel mode... permanently.

If you have an Automatic XR, don't forget to locate pin 30, a yellow wire. You will see that it is connected to a small guage black/red stripe wire. Disconnect them. Look up along the rightmost air duct for a black/white stripe wire taped to the ducting. Pull it down and connect it to the yellow wire.

Follow big VAM installation procedures located in the archives and encyclopedia.

Now, put your engine back together and enjoy. Antonius' car ROCKS!


ate: Sun, 14 Nov 1999 23:06:04 -0500
From: Dims <dimswits@IX.NETCOM.COM>
Subject: Re: LA3 Install - VSS and Premium switch

>1) Somewhere along the line somebody mentioned that without the
>hooked up there were some minor drive-ability issues. But since
the VSS
>on the '87/88 TC is designed to work with an electronic speedo, I
>see any way to work it into the picture.

Well, Brad, I've spent some time doing research on this for the T5
into the Scorpio with the Autometer mechanical speedo I am
installing. It
will DEFINITELY be possible to use a VSS, and here's how (NOTE:
this will
not work for T9 equipped cars. T5, C3, A4LD only).

You'll need:
1. A VSS from any american ford that has one. They will accept
cable AND the electrical connection (even cars that have no cable
have the
right VSS).
2. The connector for the VSS with a few inches of wire.
3. The speedometer cable from ANY american ford that has a VSS and
(Mustang, LTD, LTD2, Monarch, Crown Vic, TownCar, etc...)

The speedo cable from any ford will fit right right onto the XR
speedo with
no modification. Turns out they are standardized! After
installing the
new speedo cable, you can install the VSS in the tranny, plug in
the cable,
then make your electrical connections. Problem solved.

>2) Has anyone who has done this install kept the regular/premium
>I have the switch along with a short run of wiring (pulled from
'88 TC),
>so I figured I'd go ahead and wire it in.

I've got a little duckbill switch just beside the Scorpio's steering wheel just for this purpose.


Dimitri -- New York City

Date: Mon, 21 Feb 2000 21:59:30 EST From: Don Sweigart <Gudgls@AOL.COM> Subject: XR to TC-LA3 EEC wiring procedure

This is Only the EEC pin placement part of the job.
Read all the other posts for the rest of the conversion procedures.
Step 1: Pull out pin 43 and push it into pin 27. This connects the VAF signal.
Step 2: Pull out pin 25 and push it into pin 43. This connects the VAT signal.
Step 3: Pull out pin 32 and push it into pin 31. This connects the boost controller signal. Step 4: Pull out pin 35 and insert it into pin 33. This connects the EGR signal. (This is the hardest pin to move because of the length of the wire. Cut the tie wrap that connects the main EEC harness to the other harness to give yourself more room to work, reattach later.) Before proceeding you need to get three wires that have the pins attached from another EEC harness.
Step 5: Put one of these EEC wires with a pin into pin 2 and attach the other end to the brake switch side that doesn't have voltage unless the brake is applied. This connects the Brake on-Brake off signal.
Step 6: Put another EEC wire with pin into number 25 and run this out to the colored lead of the ACT sensor. This connects the ACT signal.
Step 7: Put the last EEC wire into pin 24 and attach it to ground. This connects the fuel mode signal to permanent premium mode.
Step 8: Attach the other wire from the ACT sensor to ground. This is the same as connecting it to a signal return wire. You can do it either way.
If you have a problem you can check the wiring by removing the harness and checking the continuity of these circuits. Thanks to everyone who figured this out.