Hello

I have a 2004 Sierra 2500 LT 6/L pickup crew cab. A month ago I started having problems with my four wheel drive. a CO 327 was read after going on the form I found that it was my tccm. I replaced the tccm and found there was no change. I then a new actuator motor was installed. The 4wd worked for about 15 minutes and then the light on my control button when out. And then I bought a brand new control button and installed it. It worked for about 10 kilometres and then the light went out again. I would also like to note that my pressure gauge and my volt meter started to act up prior to this problem and they did not work. My speedometer also started at 20 kilometers per hour and then started working a after one day. When I installed the new four wheel drive switch the oil pressure gauge started working again. I don't know if I have a wiring problem or do I have an onboard computer problem. would it be best to take it to a dealer and bite the bullet?