Cruise control inconsistent

[Bryan Beamon]

Cat C9 with 400hp with Pac exhaust brake will not turn on. I have cleaned all the connection below the drivers seat and found that the cruise will  only works by depressing the resume button.all subsequent  attempts  to activate  the cruise failed. Everything else on the smart wheel works.
The exhaust brake is on which according to info says the cruise should function  and it did for many years.

[Steve Huber]

Br
The following relays are in the circuit. Try checkiing/replacing them one at a time. If no change the existing one is probably ok.  R16, 18,  25, 33.  There is also an exhaust brake switch located in the shifter harness. If no joy on the above, my guess is that the problem is being caused by the clockspring in the smart wheel.
Steve

[Bryan Beamon]

Thanks Steve, will try what you suggested