Cruise Control...Again

I refitted my 98 with CC and have been fiting to get working since. I grabbed the switches, clockspring, PCM and Servo from the donor along with the servo connector as I assumed (rightly as it turned out) that the connector on the XJ would be corroded.

What I know:
The PCM is good (tried a spare)
The switches at the wheel and the clockspring are good (it arms, light comes on when armed)
The brake light switch is good (replaced...)
Vacuum level at the servo is good (have 18, only need 10)
The servo has been swapped.

I recently obtaind a FSM for the 98 and it led me to a couple of tests.
What I found was that with the system armed, I have 13.98VDC at the brake light switch (yellow/red trace wire) with the switch is activated, i.e. the brake lights are on, switch dangling by the harness. Obviously, no output to the servo as that segment of the switch is Normally Closed. When the switch is depressed back to the "normal" position, the voltage from the PCM goes away. Allowing the switch to move back to the operating position, the voltage does NOT come back. The XJ has to be shut down and restarted. At no time does the cruise indicator shut off. Swapping the PCM does not remove this problem.

I have looked at the wiring (with a Fluke 97 meter) to confim continuity from the PCM through the brake light swich to the servo. All good, no shorts to ground.

According to the FSM, the first step in troubleshooting the system is to start the XJ, engage the CC and confirm voltage on pin 3 of the servo connector with the servo disconnected. This is where I found the no volt condition and started back-tracking it. The wire runs from the servo to the switch. The other side of the switch runs to the PCM.

Any ideas? At this point I'll entertain even bad ideas... Either that , or I'll be forced to take it to the Stealership. They want a $100 minimum to diagnose... As I am on Social Security Disability, a $100 is a ton of bucks.

Brake sensor switch need adjusting? That was my issue when I swapped CC into my '99 XJ. About drove me nuts until someone suggested that to me.

Been there, done that...

Are you checking for voltage at both sides of the switch? Does your horn work? Are you getting a CEL?

Yes on the both sides of the switch. There is input voltage at the switch on the yellow/red tracer wire and no output whe the switch is activated i.e. brakes applied. All as it should be. The problem is, with the switch in the normal position i.e. brakes not applied, no voltage on the wire from the PCM. With the switch out of the the bracket, I can watch the voltage stop when the switch changes state as I stated in the original post.

Horn works just fine.

No CEL.

To restate, the voltage from the PCM is not att he brake switch when the switch is in it's normal position. If you arm the system with the brakes applied, voltage is on the switch. Activate the brakes and the voltage drops out, the cruise light stays on. TO get the voltage back, the rngine must be restarted.

Interesting. I have a 2000 model and my cruise works fine for a while, but then quits.

Difference is, the cruise light goes out on mine. It won't turn back on again by hitting the switch. If I restart the engine, it will usually come on again and work, but soon enough the light on the dash will turn off and my cc goes away again...

I've replaced the servo and the dash switch so far...