Cruise control issue

the "clutch switch" part has been the cause two different times when cruise working sporadically in my Freightliner

 

Dunno... my newer Freightliner has cruise that must be engaged (active cruise). I can set the cruise, but my foot has to compress the pedal beyond a half inch or else, as a safety feature (drivers falling asleep) it cuts out and bogs down because the compression breaks engage (jakes on when cruise is on, automatically).
Can't speak for the AC. Mine stinks, but still functions.... been running this thing too hot for too long.

 

Is it possible that the brake pedal is bouncing due to bumps and that is turning off your cruise? I've had that several times in several Volvos. Try this experiment, when you are on the highway put your foot under the brake or clutch pedal and raise the pedal up. Set your cruise and see if your problem goes away. Does your cruise fail to start holding your speed or does it turn off while it was holding your speed? If the brakes/brake pedal has enough slack in it it can appear to the cruise-control like you've pressed the pedal, which would deactivate the cruise-control. BTW, everywhere above where I wrote brake pedal, it could be your clutch pedal, if you have one.

Maybe you just have grime in the cruise-control switch. while truck is turned off, not running, try exercising the cruise on/off switch from fully on to fully off, over and over. My Volvo cruise controls are on a lever on the left of the steering wheel, like a turn indicator lever. If you want to get aggressive, spray a tiny amount of alcohol on the switch and then turn if on and off over and over while the truck is off. This might clean up the grime, if it's the cause.

 

Brake pedal switch
Clutch pedal switch
Trolley brake switch
Dash switch
Wire short (Happen more often when you hit a hard bump?????)
Computer (Any codes that are voltage related?)

 

Could be speed sensor on transmission but your speedometer would probably be having trouble also. You could also try setting your idle up while parked then start wiggling wires behind dash and under hood to see if it effects it.

 

Or you could get #### faced and take a nap

 

I drive 2005 Volvo day cab,and I have the same problem ? It's been to the shop several times. They drive it a couple of miles on the hwy and say its working ok?
I go through the same procedures you do.

I have the same problem! I drive a 2005 day cab, 10 speed. It's been in the shop several times for this problem. If it works at the start of my day, I don't turn it off.
If they (Volvo) find a solution to this,I will post it.