Cruise control Schematic

91 XR7

Registered User
Windering if anyone has a Wiring Schematic for the cruise control system on the '89/90 SC's (T-bird or cougars) ???

I'm looking into converting my '89 XR7 into a 5spd.. so just incase i have to do alittle bit of wiring.. it'll be nice to have :)
 
My '92 SC was switched from an AOD to 5spd by previous owner.
My cruise doesn't work and I found the brake\clutch sensing switch bypassed with a piece of coat hanger holding it always 'pushed in'.

Found this was needed to start the car. I'm not sure but I think the previous owner swapped all the harness\electronics\switches out from the 5spd.
This is probably the clutch inter-lock switch but there appears to be no brackets for it to mount to and attach the plunger rod that is hanging there.

So with the switch always 'pushed-in' the car will start but the cruise thinks you always have the clutch pushed in, canceling the cruise.
Other than that it's been a good swap, along with the auto 3.27s back there, lots of pull.
 
I had an entire printout of the schematic and troubleshooting for the cruise control system. It was like 30 something pages. I think it's in storage somewhere in Michigan and I live in MS so I can't be of much help.

I think you may be able to view the schematic in the back of the haynes repair manual but I don't know if it's the same for the 5-speed and auto. I'd try to scan the stuff I printed out from work a while back but like I said it's stored away somewhere.
 
There is no difference in the cruise control wiring between the auto and manual SCs. The only difference is that the manuals have a "clutch triple function switch" and the autos have a triple jumper instead of the switch. One of the three switches in the clutch triple function switch is used by the cruise control circuit. This switch is closed when the clutch pedal is released. In the autos the contacts for this switch are always closed by the jumper.
 
Thats assuming you have that "jumper" set up. My '90 and the other '90 auto I pulled apart had no harness or plugs for the clutch switch.

To properly wire in for cruise support requires running wires from the donor clutch switch (in my case the donor is a '90 5 spd) through the wiring harness going to the tranny over to several plugs at the EEC, which actually does feed the EEC that the clutch is in.

Its a loop that is created leaving the EEC, through everything back to the EEC. The other set of wires are for the neutral safety and it has its own set of wires mods to fully wire in properly.
 
Just a Gerneral Rewrap, But last i knew of the Cruise control was part of the EEC on the '89-90 cars.. Hence why i wanted a Schematic For it to know what's what.. I have one for least the '91-93 (have a '91 EVTM) And it what i used to convert the wiring on my '91 over to the 5spd setup..

watsonlk:
With the Tripple function switch in the position that will allow it to always starts will stop the Cruise control to work, if it was wired that way.. Chances are the Plastic clip that holds the Tripple function switch into place broke (happened on my '91)

fturner:
You are correct, I do have the pigtail for the Tripple function switch (With bypass).. which suprised me, cuase like you, i never seen one in a '90 car either.. Even after helping swap out harnesses in the dash for a Fellow Club member.. never seen it..

when i started to collect parts for my '91's swap, I got the pedal assembly (along with the Tripple function switch and pig tail, ect) and the '90's only had 4 wires on the pigtail (Start and EEC?).. the '89 i have has 6, just like how i ended up wiring it on the '91 (To 1991 Wiring specs of Cruise, Start, EEC)

With my '91, since it was a 5.0L, it had nothing to do with a 5spd, so i had to wiring in the whole Neutral circuit.. Even get the added Terminals for the plug under the dash that the tranny harness plugs into.. I know i'm using pin 30 (NDS?) but forget if i'm using the Signal Return one or i just grounded the other half of the circuit.. :confused:

the-big-e:
Heh if i had a fax machine that would work out so well...
 
I've taken pictures etc of what wire goes where when wiring in the '90 setup. In the '89 the 3rd set of wires where actually for the cruise control cutout, as well as the wires going to the EEC and start. Guess in '90 they figured they'd let the EEC do it anyway.

Its actually not complicated to do and I've figured out I can unplug the relay used for the brake pedal starter cutout and wire in the clutch switch at that point. The EEC wiring is pretty much running both wires to/from the EEC area and tapping into the wiring harness going to the tranny.

I'll dig up those pictures and see if I can quickly describe what they are.
 
IS it only the '90's that have the `push the brakepedal' to start feature?? since i know my '89 it's not needed... or least i believe so :eek: (Having 3 MN12's that you drive, it gets confusing at times)

It's kinda funny how Ford rewired/redid the wiring for 90 just to basiclly revert back to how it was the year before for the next model year..

For my '91, when i rewired it for the 5spd, i left myself a `Pigtail' that will allow my car to start with out my foot pressing on the clutch pedal.. BUT it's using the Neutral switch (that the EEC used) to lock out the starting if the car isn't in Neutral.. I just have yet to hook up a relay too it :)

But be cool if you can do something with those pictures...
 
Here are the schematics for the 92 model year. It's possible that the 89-90 cars have different wire harnesses for autos and manuals. Someone with a 1989 EVTM should be easily able to verify this.
 

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I did a 5 speed swap into my 90 with an 89 donor car. I dummied up the push brake to start switch (yes it plagues only the 1990). I installed the switch on the clutch pedal so I have to push the clutch to start. I lost cruise control and I don't know how to read wiring schematics. Any of you guys have cliffs notes on getting my cruise back? I swapped the main tranny wiring harness to the 5 speed as well. Pics would be a great help. Would it work if I disconnect the clutch pedal switch and re-install the jumper plug it had from when it was an auto?
 
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I'll work up a blurb as well with the pictures. I had a 5 spd and an auto dash board with wiring lying side by side and compared everything with the help of the electrical diagrams.

I'll see what I can do.
 
Jeremy_K:

your '90 had teh jumper plug on the pigtail for Clutch pedal switch??
If you look at Picture 5 of JD's post.. you can see the section we're talkign about (tripple function switch/Bypass plug) and typically (specially for 91-93 cars) the cruise circuit would be the Red with Light Green That goes to the Cruise Control Module.. (OR EEC in the '89/90 case) and the Light Green goes to after the Brake light switch..

So if that Red with Light green wire isn't hooked up right.. cruise will not work, Since that Lead at the EEC (89-90) or Cruise Module (91-93) is trying to sense a Ground.. and whenever ground is droped (By the TFS or Brake pedal being pressed) it shuts down the cruise control

NOW hopefully Fturner will have the correct pin at the EEC to say which one is which.. then you can see about it..

Also picture 4 Shows you where those contacts should be.. on a 1990 car.. Contacts 3 and 4 are not used.. Since Cruise Control uses 5 and 6 to get it's signal, but those contacts are normally open (not allowing current flow) which the Cruise typically needs a Closed circuit there..

Confusing.. yes :)

Hopefully Fturner can clear things up.. I'm just hoping i do not end up loosing cruise control or the EEC knowing when it's in Neutral/freewheeling or not..

Also i'm been debating on buying the EVTM for my '89 and '96.. and replacing the shopmanual for my '91 (it's getting rough around the edges :( )
 
Yes, my car had a jumper plug on the clutch switch pigtail because it was originally an automatic. I saved the jumper plug just in case that clutch switch ever broke, I would be able to start my car. Is the triple position switch the one that attaches to the clutch pedal (a black plastic cylinder with a pushrod)?
 
Maybe it's a cougar thing?? Since typically the '90 SC cars didn't have the Pigtail with the shorting plug in them if they where autos..

and yes the TFS is the black cylinder like thing that is attached to the clutch pedal with a pushrod attached to the Clutch pedal arm itself, and the Switch held on to the Pedal bracket by a plastic clip..

you COULD try replacing the Jumper back into the pigtail and see if your cruise control works again.. if so, then the TFS is no good/broken.. :)
 
If I did this correctly this should be everything in the 1990 EVTM book about the speed control including the how it works page and the so called troubleshooting page.
It should say speed control on my file instead of sensor.
It is a rather large pdf, but easy to save or print.
Hope it helps

http://members.cox.net/mechanicdbd/speed sensor_1-7.pdf

Take Care
dbd
 
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I just figured my '92 out and the cruise and clutch interlock work fine.
The clutch, brake or cancel button shuts down the cruise. It is rock solid, but I wired in a clutch interlock bypass, in case the switch bracket I built ever fails.

The problem was the switch's plastic switch clip had broken loose from the steel bracket coming off the firewall. The previous owner had painstakingly created a 'always down' bracket for the switch to allow the car to start, but the cruise didn't work since it sees the clutch as depressed all the time.
I just built a bracket and screwed it into the firewall bracket, put the e-clip on and one test drive later, everything works like new.

On the bypass switch I put in for the clutch interlock, I just tapped into the Red\Light Blue wires coming off the switch, they are beside each other on one end of the connector. The EEC looks for them to be connected or closed for the car to start, and the other end of the switch to be closed for the cruise to work.

I wired in a rocker switch, that when flipped will allow me to start the car without depressing the clutch, like when I'm working on it, and I always check to make sure it's in neutral EVERY time. It effectively connects the two R/Lb wires together. IF left on this has no effect on the cruise, it still works fine, since it's a separate switch segment.
 
Ok here's a couple of pics and I hope a bit of an explanation. Now the wires I'm adding are from the donor car and are related to the plug you need to wire in for the clutch switch. I also used the copper ends on those wires that I actually pulled out of the connectors, its a pain, but I'm trying to make it easy to reverse the install and keep everything clean.

1. Pic dsc00632 and dsc00633..
These are located on the pax side under the kick panel below the EEC. If you look at the black connector, you can see the purple/yellow wire going into the connector. The auto's don't have a wire in that slot in the plug, so go ahead and hook up the purple/yellow there.

You see the two blue plugs there? The car only has one ;). The one with several wires going into it is the one you want. The wire your interested in is the red/light blue wire. Now here's the catcher, and maybe the above diagrams will help you, as it seems one of my few brain cells have left me and I can't remember if you need to splice that red/lblue wire onto the existing one or replace the existing one. Another gotcha is, this red/lblue wire actually is spliced onto the grey/yellow wire you will see at the transmission connector and the clutch connector. Anyways....

2. Pic dsc00635 is the connector to feed the wiring harness going to the tranny below the center console at the dash. You can see here that I have wired in the purple/yellow wire from above into there (The purple/yellow wire actually t's off from the wire coming from the EEC side and goes here as well as the clutch wire harness) You will also see where I wired in the grey/yellow wire into the connector. The clutch connector has these wires.

3. Pic dsc00637 deals with the starter interlock relay from the brake pedal. You can wire the clutch switch into both the red/lblue wires on that connector and that will bypass the brake switch.

Hope that helps out a bit. This is for the '90 auto's only as I am sure the other cars are different.

Good luck.
 

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Like to thank dbd, Fturner and JD for the Pics and Info

Thanks to dbd, i got the info i truely wanted.. :)

IF only Ford made it so that all the cars where the same from '89-95.. :rolleyes:

Fturner, it looks like you Spiced in the `signal return' wire at the EEC (pin 46)? (Grey w/ Red typically, 91+, Black w/White '89/90??) and then used the orginal Red w/Blue wiring (after the Spice from the Tranny harness conection (dash side of Connector C210 :)) ???


Anyways.. with the PDF dbd posted , and maybe he'll be willing to look it up better (well the start/igintion part)

Confusion.jpg


The part circled Confuses me.. Since Terminal #46 is typically Ground at the EEC.. Pin # 30 at the EEC Sense the drop of Ground.. (Via a Open Circuit or Postive current from the Igintion switch in the start postition)

NOW say you have a Manual like is wired in that Diagram.. NOW you push in the clutch, which closes the contacts and allows the ground from #46 to go towards #30.. NOW you turn the key to the start position sending Postive current down the `Gey with Yellow' wire.. wouldn't that short out the EEC?? :confused:

OR am i missing something here :)
 
The part you circled is the splice I mentioned about the red/lblue wire becoming the grey/yellow. The splice is actually located about the middle of the dash in the main wiring harness if you had a 5 spd.

Why Ford would do something like that who knows :cool:
 
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