I have a 1996 2500 2x4 slt regular cab with 55,000 original miles. The most its ever towed was an enclosed 24' empty car trailer weighting 5k.

In the last 6 months when set on cruise on the highway if I hit a bump or pot hole the cruise will disengage.

Sometimes the on and off button for the cruise does not work either. Meaning, to turn it off, it won't turn off and to turn on, it wont turn on.

Now on my last trip from Ohio down to Arkansas even when I have my foot set on the accelerator pedal the RPMs jump 200 RPMs if I hit a bump. So if I'm driving 65 - 1750 RPMs....... I hit a bump the RPMs go up to like 1950 RPMs.

Is it sensors ?

Could it be a bad cruise switch ?

Is my trans or torque converter going ?

Thanks !

 

Sounds like the brake light switch causing the dropout on bumps. On a bump the switch will open, causing the cruise to cancel and the torque converter to unlock at the same time. Try using the cruise on the road while pulling up on the brake pedal with your left foot. The problem should go away while you do this.

As far as the switch not working, my 96 has started doing this, and I find if I press "on" and "set" at the same time, it will work. I suspect a failing switch.

 

Yep, I would look at the brake pedal switch first.

 

torquefan thanks ! Its fixed thanks to your advice to replace the brake light switch !

 

yup, causes unlock on the converter- I use this "feature" when climbing grades on slick ice to get better smoother traction, the cummins torque can break loose the rear end with ease when locked up.