My cruise control doesn't set- it turns on just fine, but will not set at all.
This started after an off-roading excursion knocked the vacuum lines off the tubes on the front of the skid plate. I can tell when that happens because the 4x4 light stays on and I have no cruise. I pulled into a rest stop, parked on the curb, and put the lines back. The light turned off, but still no cruise.

Since then I have checked the module as good as I can, replaced the brake switch, checked the neutral safety switch, and the speed sensor.
However, I may have found an issue.
My Haynes manual states the speed sensor reference voltage (orange wire to black/light blue) should be 8 volts, but its reading 5v. The other wire to ground reads 5v as per spec. I checked this with the ignition on (engine off), tranny in park, battery voltage normal.
Would the lower voltage throw off the cruise control system to cause it not to set?
I have no indicator lights and no CEL. My speedometer appears to work as it always has and has no stutter/jitter/bounce/wag/etc. All systems appear to work just fine, except the cruise.

 

Reference voltage should be 5 volts. Think that is a misprint in the haynes manual.

Have you verified that the switches work?

 

I have removed the switch module, disassembled it, and cleaned it.
I then tested the resistance of the switches and they're all in spec.
The light comes on when I push the on button, but no matter what buttons/combinations I push will the servo take the throttle.

 

Do you get a vacuum supply at the servo? I think all the pcm does to regulate speed is to either vent, or apply vacuum to the diaphragm? (according to the 01 manual...)

 

I just checked vacuum. 15-20 inches of mercury at idle. Drops as it should when you open the throttle.

 

Are the vacuum lines reversed?

 

I don't think they are..
How could they be?

 

The 4X4 light.
Was that on after you put the lines on or before?

I think in rereading you're 1st post you meant that you knew the vac lines were off when the 4X4 light stayed on.
I first read it as the 4X4 light was on and the cruise didn't work, and thought that the lines were reversed.

 

Oh, ok. No, those lines aren't reversed. The 4x4 light staying on was my indicator the lines were off. They're different lengths and the light turned off so they're on right.