Cruise control install issues - stumped

Okay so this should have been simple... Cant track down the issue in my cruise control that I installed. sorry in advance for long post.

2000 Cherokee sport, aprx 130k miles

Problem: cruise control will not come on/stay on. when i push the on button on my steering wheel the cruise control doesn't come on. When I first start the vehicle and push the button the light will come on for a second and go off. Usually it will do this once or twice and the nothing happens when i push the button. sometime is will stay on for a little longer but then if i touch any other buttons, such as 'set' it goes off.

Backstory: A couple weeks ago i pulled cruise control from a xj with a blown motor. took clock spring, buttons, servo. I installed it and it caused all types of problems. Jeep ran like crap(read something about TPS and CPS and the horn relay), airbag light, check engine light. So I figure I have a bad clock-spring at this point. Go to the junkyard get a new clockspring, while i am at it I pull another servo.

before I installed the second clock-spring I tested the continuity of the junkyard clock-spring with a multimeter, from the pins on the back of the clock-spring where it takes the plug from the steering column, to the end of the connectors where the airbag, horn and cruise wires plug in. Continuity checked out so I installed the second clock-spring. This cleared the airbag light, cleared the check engine light, jeep ran fine again. But, the cruise control doesn't work. Push the button light comes on, doesnt stay on.

So I though maybe its because im not driving at highway speeds, however when im driving on the interstate and push the button, nothings happens, sometimes if i hold the button down the light will flicker. one time i pushed it and the cruise light came on and stayed on for like 2 minutes, but as soon as I touched 'SET' it shut off. Question here: can the cruise control system be turned on when the car is under 35mph, like the light will stay on? you just cant set it right? anyway....

So I thought maybe it was the switches. took them apart to expose the resistors. checked resistance. seemed okay. values were as follows:

Left hand resistor in middle position for when no switches are pressed read 20.48k ohm
ON/OFF resistor read 465 ohm
SET resistor read 5.49k ohm
RESUME/ACCEL resistor read 15.37k ohm
CANCEL resistor read 1.24k ohm
COAST resistor read 2.96k ohm

researching says they should be:

Switches resistance values: 20k resistance when no switches pressed
Clicking the:
on/off = 500 ohm
Set = 7k ohm
Resume/Accel = 15k Ohm
Cancel = 1.2k Ohm
Coast = 2.9k ohm

Tolerances: Roughly 10%.

So buttons seem like they should work? at least enough to turn the systems on? So then I thought well maybe i have another bad clock-spring so i rechecked the continuity to see if i maybe dickered it when installing, all read fine. to double check the switches I ran jumper wires from the steering column connectors to the cruise control wires - acted exactly the same as when plugged into the clock-spring, light came on for a half second and shut off. Checked the wiring for the cruise control between the switches and the clock-spring for continuity. it was good.

So I moved on to thinking maybe it was the brake light switch. I had replaced the brake light switch in the last few months. Readjusted it: plunger in all the way, then out all the way, reinstall, push brake pedal to set the position. no change. brake lights function as they should. repeated just in case. same thing.

So I thought well better check the servo. Note: when i installed the servo the connector from the harness on my jeep for the servo was there as it should be, however it was too short, so I cut the connector and spliced in about and 8 inch piece of wire to each of the three wires that run to the connector to extend it. good connections, properly stripped, twisted for mechanical connection, soldered in place and heat shrink wrapped each one. used 16 gauge to match factory. have double checked the wiring and connections several times now. So I next I took the servo half apart to inspect. looked good, clean inside, clean connectors, sounds like a air pump when articulated, so I think its functional. I swapped it with the other one I had anyway to check and there was no change.

Vacuum line that connects to servo seems to have good vacuum pressure, holds to my finger and hisses when not plugged in. if I unplug it after turning the jeep off it hisses loudly when it releases pressure.

The servo and cruise control buttons are from a 2000xj and the part number on the switches is the correct on for my later model ending in 30AD and 31AD. The clock-spring is from a 97xj because the one from the 2000 didn't work but the part numbers are identical.

What am I missing here?

Am i right to assume the clock-spring is okay if the continuity between ends checks out? Is there a way to test the servo itself? Do these servos fail easy? seems like I wouldnt have too bad ones that don't show any signs of damage. Can I check the wiring from the cruise control on the engine bay side? Seems super weird that it tries to come on, or at least the light and then shuts off.

Determined but I think I hit a wall with the limit of my understanding of this stuff.

Thanks in advance.

What year jeep did you pull the switches from?
The cruise control switches are very year specific. They will not interchange between years.

There are plenty of threads on here about the switches and what part numbers work with what years

You may need to have the ecm reflashed to accomodate the cruise control option.

My 99 I added cruise just like you described and I did not have any issues.
I think it would be a good idea to get a scan tool on it and look to see if you are getting cruise request when you press the button.