My '97 has a very weird problem. The cruise control light will only stay on for about 45 seconds. Everytime the ignition is started, it re-sets this "timer" and again the cruise light on the steering wheel can be turned "on" with the "On" button, but only for about 45 seconds. Even just idling in the driveway without ever turning the steering wheel, the light only stays on for this brief period. Same thing if driving. And it cannot be turned back on until the truck is shut off and re-started. Horn works fine, and the air bag light isn't on either. The actual cruise control itself doesn't work either.

 

I would still check the wiring in the steering column....

Cruise buttons just send a specific voltage down the wire to the PCM to suggest what it should do anyway. PCM actually controls everything else.

 

I'd check vacuum lines too.

 

if I use cruise the light stays on until I turn the truck off even if I haven't set a new cruise speed or resumed a cruise speed after hitting the brake etc.. for a long time.

 

I think.. and I may be wrong.. But I think some of the cruise control components are under the battery. corrosion from the battery can dirty them up. something to look for.

 

+1, that's why I suggested a vac problem.

 

I removed the battery and tray and everything looks fine on the cruise thing there.

I know I have a very slight vacuum leak, but its so slight that my vents go wild only when its minus 10degrees or colder and I go up inclines on the freeway. Otherwise, I would never suspect a vacuum leak. 4x4 works fine all the time. I have checked all vacuum lines and check valves and they all appear to be in good shape.

 

Cruise is turned on/off by the cruise switch sending a modified voltage signal to the PCM.

Power comes into the switch from the PCM...... When you press the on/off button, voltage goes thru a 909 ohm resistor, back to the PCM. Signals from the set/coast, resume/accel buttons are just different resistors, that modify the voltage but send the signal down the exact same wire.

I would begin to suspect the switches in the steering wheel are getting flaky..... at least, the on/off button...

 

I'll stick with vac leak. Does not matter how small. Find it,fix it and go from there. I'm also heading to the JY this Saturday. I'll pull an "on/off " switch for you if you care to purchase it. My switch also went bad, but that was it, it didn't work at all. Which is why I suspect a vac issue, since it works but only for a short period. The switch either works , or it doesn't. Another thing to look at would be a faulty brake light switch.

 

I just removed, dis-assembled and cleaned the switches in the steering wheel. Same problem persists. Light can be turned on for 42 seconds, then it turns off. Cruise never works, not even while the light is on for those first 42 seconds.