'98 Cummins, weird cruise control issue

I've had this truck for about 6 months now. Up until recently, the cruise control has worked fine, but a couple months ago began to occasionally quit working until the truck was shut off and restarted. The light on the instrument panel would be on, it just would occasionally quit. This might occur every few days. However, beginning a couple weeks ago, it has been inoperable almost all the time. Here are the current symptoms:
The "Cruise" light on the instrument panel will only come on after pressing the "On/Off" button several times, usually 4 times. The first couple of times that it's pressed it does nothing. On the 3rd time the "Cruise" light barely flickers but goes back out. The 4th time it's pressed it comes on and stays on but the cruise still does not work. If I'm not mistaken, this doesn't sound like the classic problem of the "vacuum hose under the battery" issue, correct? Any ideas what's going on? Is it likely a defective switch in the steering wheel?
In case this is relavent to the problem, ever since I've had the truck I've had problems with the ABS and brake lights being on. I've switched out the speed sensor on the top of the pumpkin but it still happens. On Saturday my buddy found a signal light wire that was grounding out and blowing the brake light fuse. Since that time those lights have not been lit nearly as much as before but still come on part of the time. Any suggestions?
Thanks in advance!