How to Retrofit a 1991 Cruise Control system into any Gen 1.

[Jay Ayala]

Hi guys, and welcome to the documentation on How To "RETROFIT" a Cruise Control into ANY Gen 1.

This thread will help anyone determine if this is a feasible project for him to try. The goal of this thread is to formally document how I performed this retrofit on my 1989 Dodger Raider. I have completed the project and it is 100% operational. It took me a really long time, a lot of research, a lot of verification, a lot of effort, and a lot of determination. My body is actually sore from this job. Hopefully all of us Gen 1 owners will now have the option of having a factory Cruise Control system. I've have done a lot of legwork that I will share with you guys on the message forum. The job really is up to you to perform.

• Back story:

As some of you might know I've been messing around with the idea of Cruise Control in the Gen 1 for some time now. My initial attempt was an AudioVox unit. It was a universal vacuum actuated unit and for the most part, satisfying. But it would top out at 68mph ± 1mph. After a trip to Kellogg, ID. (75mph speed limit on the highway) I became annoyed. So even thought I performed the job correctly, followed the installation instructions, and the aftermarket Cruise Control unit was working, I felt in my heart that I didn't successfully complete what I had set out to do. I didn't like the aftermarket unit clashing with my dashboard either. So what was I supposed to do? I found some wiring diagrams for the factory Cruise Control systems on the GEN 1 BIBLE PROJECT ftp site. Then I started comparing and verifying that all of the "Tie In" points were available on my Raider. They were. So it was time to roll up my sleeves and do my homework. I thought to my self how cool is this? I can actually get a factory Cruise Control system in my Raider! There is a difference between the 1991 Cruise Control System and the 1992 Cruise Control System. The difference is that the 1992 Cruise Control System is vacuum actuated where as the 1991 Cruise Control System is all electrical. I recommend moving the system off a 1991 on down. I removed the system off of a 1991 Montero.

• Components:

There are several parts to this Cruise Control system that you will need to perform the "RETROFIT" project. For the most part, all of the components are pretty accessible to get. The toughest part to get was the steering column combo switch. The list of the parts is as follows:

1. Cruise Control Servo motor.
2. Cruise Control/Windshield Wipers Combo switch on the steering column.
3. Break light Switch.
4. Cruise Control Computer/Brain.

• Removal from Donor:

Cruise Control/Windshield Wipers Combo switch on the steering column.
You will need to remove this unit completely. There are only two small screws holding it in the steering column. There is 1 ground wire from the Switch to the steering column, remove that along with the switch. There are 2 separate wiring harnesses that connect from the switch to the main vehicle wiring, take those 2 harnesses too. Also very important, take both mating wiring harnesses plus 6"-8" worth of wiring beyond the harnesses.

Cruise Control Servo motor.
To remove this there are 3-12mm bolts holing the servo to a mounting base. Also you WILL need to take both of the throttle cables that go to: One goes to the Throttle Body, and the other goes to the Throttle Pedal. The firewall penetration has a plastic clip that holds the Throttle Cable in place. It is very important to take your time, and be careful when removing this clip. I used a pair of long needle nose pliers to gently squeeze the plastic clips together to allow it to pass through the square hole for the firewall penetration. Also you will need to take the wiring harness. In addition you will need to take the mating wiring harness and about 6"-8" worth of wiring beyond the harness that connects to the main vehicle wiring.

Break light Switch.
The break light is different for the Cruise Control system then in our Gen 1's. Our Gen 1's have a two (2) prong break switch. Whereas the Cruise Control System needs to have a break switch with four (4) prongs. It was an easy task to remove the break light switch. You will need to take the switch. Also you will need the wiring harness that connects directly to the switch plus 6"-8" worth of wiring beyond the harnesses that connects to the main vehicle wiring.

Cruise Control Computer/Brain.
This is pretty easy to find, and very simple to remove. There are two Phillips screws holding the brain in place. Simply remove the screws and disconnect the wiring harness. You will also need the wiring harness that connects directly to the Brain plus 6"-8" worth of wiring beyond the harnesses that connects to the main vehicle wiring.

If you want, you can remove the wiring intact but that is a lot of extra work. I've done the bulk of the work in that manner and in retrospect, I could have just done as described above. It would have been a lot simpler and it wouldn't have taken me so much time to remove at the junkyard (I originally spent 4 hours removing all of the components and the wiring intact. Of course you have to remove the dash, and unwrap the electrical tape along the wiring, and it was just a mess and there are so many wires that are all different colors and similar colors I got lost several times and had to start all over.) I highly recommend doing it as described above without removing the wiring intact.

However if you plan on removing the wiring intact, expect to see this:

• Research and homework:

First things first. I had to locate a wiring diagram for the Cruise Control System. Luckily for me, the GEN 1 Bible Poject ftp website already contained a lot of the diagrams, all I had to do was download what. I had already purchased a Factory service manual for my 1988 Montero a while back ago so I was pretty confident that all I had to do was compare and verify that all the tie in ponints were available on my 1989 Dodge Raider. I took my time and found all of the tie in points and made mental notes of what I had to do to install the wires to those locations. It went by pretty fast when I had a 1991 Cruise Control wiring diagram to compare with the 1988 factory service manual. Click here to download the factory Cruise Control System documentation. (0.9 Mbytes)

• Preparation - Creating main wiring bundle:

Take your time and study the wiring diagram. Realize that there will be 4 wiring harness bundles. Your Main Cruise Control Wiring Bundle should look like this:

• Wiring harness from main bundle to Cruise Control Brain.
• Wiring harness from main bundle to Cruise Control Switch.
• Wiring harness from main bundle to Break switch.
• Wiring harness from main bundle to Cruise Control Servo.

The distance between Harness A & B should be about 7'-0"
The distance between Harness A & C should be about 7'-0"
The distance between Harness A & D should be about 10'-0"

As you can see in the picture there are several wires that need to be routed to specific spots on the vehicle. Most of these will be wire through taps no longer then 24" from the corresponding harness. I will now break down how I created each individual wiring harness and what taps come off of them. I will be refering to the wiring numbers from the diagrams so check them often.

.....Harness A - Cruise Control Unit......
Wires #10 (BLK) & #11 (WHT-BLK) are ground wires. I tied them together and ran one BLK wire 24" for ground. Wires #13 (BLK-BLU) & #14 (BLK-WHT) are OverDrive Off wires. I ran individual BLK-WHT 24" wires for OverDrive Off. (depending on if you are working with a 4cyl or a 6cyl it Wires #13 and #14 will have to be routed to the passenger side kick panel, 6cyl, or driver side kick panel, 4cyl.) Wire #17 (RED) is Computer Diagnostic connection. I ran one individual RED 36" wire for Computer Diagnostic connection.

.....Harness B - Cruise Control Switch.....
Cruise Control Unit wire #2 (BLK-YEL) & #15 (YEL) are routed from Harness A to about 3/4 and 1/2 way along Branch B as shown. I ran one 12guage BLK-YEL wire about 24" for Power. I ran one YEL 36" wire for speed sensor. Cruise Control Switch wire #3 (RED-BLU) is a power wire. I ran one RED-BLU 30" wire for power. Cruise Control Switch wire #2 (RED-BLK) is a ground wire. I ran one BLK 30" wire to Ground.

.....Harness C - Break Switch......
Break Switch wire #2 (GRN-RED) is tapped to a power wire. I ran one GRN-RED 8" wire for Power. Break Switch wire #3 (GRN) is tapped and routed to the Hazard switch. I ran one GRN 8" wire for Hazard switch.

.....Harness D - Cruise Control Servo.....
This is the easies of them all. Just don't make the actual harness connections until the wires have penetrated the firewall. That's it.

Cleaning up the wiring.
I used what is called spiral wrap to clean up my wiring. I used 1/4" spiral wrap to organize my wiring bundles. It helped out greatly in that I was able to move this wiring system around relatively easy once I got the wiring taken care of. I cut the 20'-0" length of spiral wrap into 4"-6" pieces and started at the main wiring harness. Then I just followed it out slowly making sure not to confuse what wires were assigned to which bundles. Then slowly I made it a clean connection that looked near stock. I suppose you could also use the plastic corrugated wiring conduit. But I prefer the look of the spiral wrap myself. But everyone has their particular preferences.

• Installation:

Depending on your level of organization, this part should fly by. I labeled each one of the wires that needed to be routed to specific locations with a file folder labels. I wrote what connection it needed to come to and what color wire it needed to attach to. It was fairly simple from that point on. The hard part was removing the dashboard completely and removing the blower fan. (If you have a 4cyl engine, it is not necessary to remove the fan but it is convenient.) Simply route the wiring along the main VEHICLE wiring bundle and begin to make the appropriate connections.
You will have to remove the 2-prong break switch. The wiring harness that connects to the old 2-prong break switch contains 2 of the wires that you will use, so keep these in mind. When replacing the 2-prong switch with the 4-prong switch you should have two 8" wires dangling from the new Break Switch wiring harness. Those connect to the wires that were in the old 2-prong Break Switch. See diagram for color scheme.

There are 3 tricky connections to make, other then these 3 connections, the rest should all be pretty straightforward. Also there is 1 Harness conversion that you will have to perform to allow for use of the Windshield Wipers.

Tricky connection #1: From the Cruise Control Unit wire #14 (BLK-WHT) needs to be routed and tapped into the BLK-WHT wire of the OverDrive Off Relay. Make this connection as close as you can to the relay.
Tricky connection #2: From the Cruise Control Unit wire #13 (BLK-BLU) needs to be routed to the same BLK-WHT wire of the OverDrive Off Relay. Make this about 1" further away from the OverDrive Off Relay.
Tricky Connection #3: From the Cruise Control Unit wire #15 (YEL) needs to be routed to the vehicle speed sensor. This is probably the last connection you will make. This will have to wait until the dashboard is placed back on the vehicle. Once it is placed back on, the wire should be routed to the following screw on the rear of the instrument cluster.

Tricky connection #1 & #2. See the Red Connectors off the realy?

Tricky connection #3 Best method is to use one of those screw type connectors.

Harness conversion is really pretty simple. You will have to clip the wires from the freshly installed Cruise Control/Wiper combo switch and re-connect the harness from the older Windshield Wiper switch. The color scheme for the wires is identical, and you will not have to modify anything. Just follow the color scheme and it will match up directly to the older style harness.

Once all of the wiring is in its place reinstall the Fan Blower and the dash. The Cruise Control Servo can be directly bolted to the Fender wall, that is how I installed it. You will have to remove the current Throttle Cable and replace it with the two that are connected to the Cruise Control Servo.

• Testing:

Okay the job is done now, and assuming you've made all of the appropriate connections, this will be the moment of truth. Take it for a test drive. Explore all of the functions. ON-OFF-RESUME-BREAK-ACCEL-COAST. Make sure it all works. Then you can simply enjoy everything and sit back and relax while you are on you cross-country drive to the next 4x4 trip.

• Conclusion

The project was pretty difficult. I spent a lot of my personal time figuring this thing out. I spend a lot of time researching through several different wiring diagrams and verifying that these tie in points actually existed on the vehicle. I spent 4 hours at the donor car removing the wiring intact. I spent 4hrs± creating the wiring bundle. I spent 3hrs installing the wiring and the Cruise Control Switch in the steering column. I will now spend the rest of my trips relaxing with my foot off the pedal. Now that is a worthy reward, IMHO. It took me a long time, because I was doing this for the first time. No one else on the message forum had an answer for my question. So I did what I knew I could. Overall, the project was very time consuming. But in the end it was worth it. Level of difficulty, I would say that , on a scale of 1-10, this mod is a 6. But like I said, very time consuming. Now that I know what needs to happened, I can cut the job down by about 1/2 the time at least. I was taking photographs and making notes all along the way. This next time around won't be so difficult for me. YES, I will be doing this one more time to my 1987 Montero. The Raider looks like I didn't do anything to it. It looks stock, because it is. But that was my goal.

• Closing Comments:

I really hope that this thread finds its way to those who want to perform this modification. I would really like to hear from those who choose to do this. It would be great acknowledgement if someone else were to attempt this and successfully complete it. I like the way it works, and it is good for me. I don't expect everyone to attempt this, but those who do attempt it should know that it is possible.

As always,
thanks for reading.

Jay

 

[plh]

Fantastic write up and detail. Post over at the Wire too and ask to make a sticky, Thanks for taking the time to document this project.

 

[Jay Ayala]

plh, thanks for the compliment. I posted this on the wire earlier today and also 8 years ago. It has already been archived.


Sent from my iPad using Tapatalk

 

[Jay Ayala]

Additional photos I found from the installation process

 

[Jay Ayala]

Additional photos I found from the donor vehicle.

 

[Jay Ayala]

Finalizing the Retrofit of my Cruise Control system, 11 years in the making.

 

[Jay Ayala]

 

[Jay Ayala]

 

[Jay Ayala]

 

[Jay Ayala]

 

[Zerocool]

So im going to attempt this on my 1989 montero, since i dont have all the power options, but i really would like cruise control, and since there arent any better options, i think factory will be best, now I just have to find a monty with a cruise control i can rip out lol

 

[Jay Ayala]

Let me know how it goes.


1989 Dodge Raider 3.0L

 

[LandRaider]

Will be gathering pick and pull parts this summer to exorcise the garbage aftermarket cruise setup from my diesel Gen1. Thank you for your time in documenting this Jay. I appreciate it.

 

[Toasty]

Dude! Landraider! How have you been man?

 

[Deleted member 144409]

Grab the MPI computer while you're in there. And all the other relays you can lay your greasy mitts on. I haven't got my cruise to work since I moved it (91 -> 89) and not sure if it's MPI or one of the thousands of connections I tested and retested!