Cruise Control Wiring Diagram Help

The plugs actually come apart and the wires with the ends will come out. The reason it was suggested to go easy on your plug in the Jeep is because it is a pita to align all the pins and get them in the proper spots while reassembling the plug. You can harvest any wires with the ends and install them into your existing plug to fill the blank spots if yours does not have wires for the the cruise present. Like I said check your existing PCM plug for wires at C4, C5 and C32 if you have them they are the wires you want and you can track them back or tap into them by the PCM. If you don't have them them you will need three wires and the ends from the spare plug you have and will need to drill out the plastic plugs in the corresponding spots for C4, C5 and C32. Unplug the plug from your PCM prior to drilling the plugs out. When you pull the wires from the spare plug you can use one of the blank holes to guage the drill size you want for drilling the plugs out.
 
  • Like
Reactions: Tycarver
The servo sits just below the brake booster on the inner fender on the driver's side. The exact spot is not super critical you just need the cable to loop around by the firewall and back over the valve cover to go through the same bracket as the throttle cable as long as the cable is not binding. If you don't have the plug for the servo just make sure when you put in the wiring you leave enough length to comfortably plug in the servo. There is a tray right there between the inner fender and firewall that I bolted my servo to.

You don't drill the PCM at all. The picture of the PCM plug you linked does have the correct wires in it. The plug is upside down in the image but if you look the bottoms right corner has a 1 the top left has a 32 the wire holes go left to right just like reading a paragraph. C4 is the tan/red wire C5 green/red and the C32 is the red/white. Go check the factory plug and make sure you don't have anything in those spots. If you do your already ahead of the game. If not just pull that spare plug apart and harvest those three or any other three you want and drill your plug and install them. If you look the plug over there you will see how it comes apart the wire and terminals will pull backwards out of the plastic plug body.
 
  • Like
Reactions: Tycarver
The servo sits just below the brake booster on the inner fender on the driver's side. The exact spot is not super critical you just need the cable to loop around by the firewall and back over the valve cover to go through the same bracket as the throttle cable as long as the cable is not binding. If you don't have the plug for the servo just make sure when you put in the wiring you leave enough length to comfortably plug in the servo. There is a tray right there between the inner fender and firewall that I bolted my servo to.

You don't drill the PCM at all. The picture of the PCM plug you linked does have the correct wires in it. The plug is upside down in the image but if you look the bottoms right corner has a 1 the top left has a 32 the wire holes go left to right just like reading a paragraph. C4 is the tan/red wire C5 green/red and the C32 is the red/white. Go check the factory plug and make sure you don't have anything in those spots. If you do your already ahead of the game. If not just pull that spare plug apart and harvest those three or any other three you want and drill your plug and install them. If you look the plug over there you will see how it comes apart the wire and terminals will pull backwards out of the plastic plug body.
Got it that Helps. I did not know how to read the plug before so “C32” is the 32nd hole counting left to right?
 
I also checked just now and I don’t have any of the wiring in my dash for cruise control so I’ll have to change the clock spring and run those wires as well.
 
Like I said previously check the PCM plug there are at least two other people I have run into that did not have clock springs or wiring in the steering column but they did have the correct wiring in the PCM plug. I suspect someone prior to them removed the cruise because they did not want it and harvested the bulk of the system to sell to someone else. Until you check the plug itself you really won't know. And you now know how to read yours to see if the corresponding spots are filled or blank.
 
  • Like
Reactions: Tycarver
Looking at my wiring harness now I do not have the wires I believe (posting pictures to make sure) im off the next few days so I’m gonna try to knock this out.

image.webp


image.webp
 
Yes but you start by taking apart the spare plug first to harvest the ends and pig tails. It will also let get familiar with the process before you start on the plug in your Jeep.The grey outer plastic piece comes off the the black piece. You will want that unplugged from you PCM when you drill out the plugs. Taking the other plug apart will also let you properly gauge the drill size you will need.
 
Yes but you start by taking apart the spare plug first to harvest the ends and pig tails. It will also let get familiar with the process before you start on the plug in your Jeep.The grey outer plastic piece comes off the the black piece. You will want that unplugged from you PCM when you drill out the plugs. Taking the other plug apart will also let you properly gauge the drill size you will need.
1 step ahead of you. Already took it apart and got the wires out and I just finished running them in the engine bay.

image.webp
 
1 step ahead of you. Already took it apart and got the wires out and I just finished running them in the engine bay.

View attachment 253125
How ever I just realized I have a 4th wire and I do not know what these 2 harness go to. They are in the wiring harness with the cruise control. Should I just ignore these 2 and ignore the 4th wire?

image.webp
 
The forth wire is the on/off wire yellow/red goes to C11. those two plugs are connected so leave them be for now focus on getting the four wires and their ends installed in the grey plug for the PCM. If the other ends of those wires are ran and connected the rest is faily simple. You can test the switches you have with a ohm meter to ensure they work correctly. I know the 1st set I bought were incorrectly listed for my year and had the wrong resistors. The second set were correct but the contacts on the on/off were done for so I ended up pulling the correct set and the incorrect ones apart to cobble together a working switch with the correct resistors and the contacts from the incorrect switch. On a 98 the On is 909Ohms+/-9, Set 6650Ohms +/-66, Resume 15400 +/-154, cancel 0Ohms closed circuit and coast 2940Ohms +/-29. If the contacts are bad or the resistors are wrong the system will not work.
 
  • Like
Reactions: Tycarver
The bad on/off needed to be pushed excessively hard to get it to function with the rebuilt switch using the contacts from the incorrect year it works as it is supposed to.
 
  • Like
Reactions: Tycarver
The forth wire is the on/off wire yellow/red goes to C11. those two plugs are connected so leave them be for now focus on getting the four wires and their ends installed in the grey plug for the PCM. If the other ends of those wires are ran and connected the rest is faily simple. You can test the switches you have with a ohm meter to ensure they work correctly. I know the 1st set I bought were incorrectly listed for my year and had the wrong resistors. The second set were correct but the contacts on the on/off were done for so I ended up pulling the correct set and the incorrect ones apart to cobble together a working switch with the correct resistors and the contacts from the incorrect switch. On a 98 the On is 909Ohms+/-9, Set 6650Ohms +/-66, Resume 15400 +/-154, cancel 0Ohms closed circuit and coast 2940Ohms +/-29. If the contacts are bad or the resistors are wrong the system will not work.
This is the rest of the connectors they are not connected to anything but they are on the harness with the cruise control.

image.webp
 
The one on the right is the battery temp sensor. It goes under the battery in the center of the tray the plug sits between the firewall and the battery under the PCM. The second plug is for the the wiring going to the clock spring I will have to look under my dash to see exactly where it sits but the wires coming out of that go to the clock spring (the last picture you posted when all the parts arrived the natural color plug with the BR/YL, RD/YL and RD/LG wires is the clockspring plug. In your picture it looked like they were both RD/YL but the one off by itself in the #1 pin slot is for the horn) and pass through to the little green plug for your switches. Being as your building from ground up the location probably is not super critical you just want it inside the dash next to the steering column where it will be convenient for servicing the system if it requires it. When you install the clock spring those wires face the driver and there is a spot on the bottom center of the wheel where the green plug sits.
 
Last edited:
The one on the right is the battery temp sensor. It goes under the battery in the center of the tray the plug sits between the firewall and the battery under the PCM. The second plug is for the the wiring going to the clock spring I will have to look under my dash to see exactly where it sits but the wires coming out of that go to the clock spring (the last picture you posted when all the parts arrived the natural color plug with the BR/YL, RD/YL and RD/LG wires is the clockspring plug. In your picture it looked like they were both RD/YL but the one off by itself in the #1 pin slot is for the horn) and pass through to the little green plug for your switches. Being as your building from ground up the location probably is not super critical you just want it inside the dash next to the steering column where it will be convenient for servicing the system if it requires it. When you install the clock spring those wires face the driver and there is a spot on the bottom center of the wheel where the green plug sits.
I already have the battery temp sensor under my battery from my normal engine harness. Did jeeps with cruise control have 2 or do I only need to use the one I have already?