I have an '02 Silverado 1500. Ive had the truck for about 2 yrs now with only the transmission giving me trouble. Now all of a sudden my speedometer has stopped working on me. I've checked a couple of different fuses and they looked fine to me. I'm at a loss expect to check the vss sensor. Any input would be greatly appreciated

 

The speedometer is completely electrical. If the odometer is still updating, then the speed sensor on the transmission is probably ok, and it could be the meter movement (stepper motor) behind the instrument cluster. I've replaced some of those myself a long time ago when some gauges went out on my 2003 Yukon (also GMT800). If the odometer is also not updating, I would suspect the sender/sensor on the transmission, or the wiring harness.

 

Here is the manual page for diagnosing a faulty speedometer:

Speedometer and/or Odometer Inaccurate or Inoperative — 2002 Chevrolet C 1500 Truck 2WD V8-5.3L VIN T Service Manual | Operation CHARM

 

It's important to note that 2002 was the last year where the instrument clusters were using air core motors. 2003 and up were using actual stepper motors.

Chances are excellent you've got a bad ground somewhere (probably under the dash) or the air core motor is giving out. Anecdotally, when I first got my 02, I was told the AC works, but he never used it because when he turned it on, the instrument gauge would completely go dead and would require waiting over night with battery disconnected for it to resume working. To me, this screamed electrical gremlin, and as the AC system was actually dead, I ended up replacing the entire AC system in addition to cleaning every ground I could find (I believe there's 2 or 3 under the dash) and my AC and IC have worked simultaneously ever since.

Now, if you're unlucky, the air core motor has failed. These are no longer produced, from what I've been able to gather. You can still find NOS, but we're talking about 20+ year old electrical motors. There's a chance you can send your cluster in to have it repaired and the motors oiled up, but it's a crap shoot. The best solution, in my opinion, is to undertake a sizeable project that utilizes a 2003-2007 (I think those years are right) instrument cluster. The plug on your 02 will fit physically, but the wires are not in the correct spot. My opinion is that a pigtail should be created that plugs into your existing connector and then reroutes the wires to a new connector which is fitted for the 2003+ cluster, eliminating the need to reconfigure your original plug. Doing just this, your oil pressure and volt gauge (and obviously DIC) won't work, but speedo, tach, gas and temp will. Odo will need programming to be correct, but from what I've read, it's not terribly difficult.

These appear to be your choices, assuming these 2 scenarios are among the source of your problem.