Wiring Help

[OldPonyGuy]

I am going to put an XR4Ti engine in a 75 Mustang II hatchback. I will utilize the stock XR4Ti wiring harness and adapt it to the car using an LA3 ECU. There are two connectors on the factory harness going into the cabin of the XR4Ti. One is for the ECU, and the other is a connector with five wires. My problem is I don't know what those five wires go to inside the XR4Ti. I have the wiring diagrams but cannot for the life of me find the destination of these five wires. They appear to be the following colors:

red
green/grey
white/green
grey/black
blue/green

Any help identifying where these wires go would be greatly appreciated.
Ted A.
(OldPonyGuy)

[jkxr4ti]

Just looked at a harness in the Garage. That one looks like it goes to the ignition switch through the body harness. Thats C134 in the EVTM

The colors seem to be different than in the EVTM though. Ill try and look for the body wiring diagram and see what these are.

[OldPonyGuy]

Jeremy, that would be great. Thanks.

Ted
(OldPonyGuy)

[jkxr4ti]

wow, you got a good one here. Its not the ignition switch as i originally thought. Its actually C101 and apparently this is a model year variation. The 86 EVTM and schematic I have show C101 as a 2 pin connector but the 89 EVTM shows C101 as a 6 pin connector with 5 populated positions. Thats probably why you couldnt seem to match this up. The harness I have in the Garage is from an 88 so it has the connector just as you describe. You really need to be looking at the 88-89 EVTM for this one.

Here is the 1989 EVTM http://www.merkurxr4ti.com/ref/(03)1989 ... 20EVTM.pdf
and the 1986 Schematic but as I said this has a 2 pin instead of a 6pin connector http://www.merkurxr4ti.com/ref/1986XR4T ... agrams.PDF

This is what i find...from the 1989 EVTM and ohming out the harness

Red is sourced from the EEC relay red wire then goes to the Black/red wire on the body side of that connector (pg 90) this goes on to the inertia switch

green/purple (you thought green/grey) goes to the AC deicing switch on page 91 of the EVTM. On the body harness this is Black/White to the ACwot cut out relay

Tan/Green (you thought White /Green)goes to the VIP connector on pg 29 of the evtm this also goes to a small brown/white wire on the body side of this connector and that goes on to the Fuel pump relay circuit see pg 90.


Gray/Black goes to pin54 of the EEC and is the AC WOT cut out relay. on the body side of this plug its Brown with Green. Also see pg 18 and 27 of the EVTM for this.

blue/green goes to Black/Blue on page 92 of the evtm this is for the AC recirc solenoid.


Hope this helps out Ted

[OldPonyGuy]

Jeremy, That is fantastic! Thanks so much for your time and help.

Ted

[OldPonyGuy]

Jeremy, I clicked on the link for the 1989 EVTM you supplied, and my computer downloaded the file, but I got a message asking for a password to open the file.

Ted

[Ray]

p/w is probably xr4ti all in lower case letters.

[jkxr4ti]

Hey no problem, I like a good wiring challenge. I actually didnt realize that there was a difference between the early and late engine harness. I was looking at my 86 evtm and my 88 harness first and it had me scratching my head a bit until i looked at the 88 evtm.

[OldPonyGuy]

Ray,

That did it. Thanks very much!

Ted