Strange Problem....VSS???

[txkfx400]

The other day my speedo quit, ABS light came on and OD light started flashing. Scanned the truck and pulled p0500 code. Everything points to a bad VSS. After a couple of miles, speedo started working and ABS and OD lights went out. A few days later, same thing and no turn signals or cruise control and the heater temperature control quit working. After about 40 miles everything went back to normal. I do not know if the heater, cruise and turn signals were working or not the first time since I only drove 2 miles max before everything started working again. Could the VSS be tied to the heater or turn signals in some random way? It does not seem they would be, but who knows. I am going to get a VSS tomorrow and see what that does. Any ideas would be greatly appreciated. I hate electrical problems and was hoping someone might have had similar symptoms. By the way, truck is a 2001 7.3 4x4 with an automatic. Only mods are 4" exhaust, Tymar intake and Edge Evo II set on tow. Thank you in advance.