The cruise control on my truck is inop. I just got it back from the dealer and they say that the issue is in the reluctor gear in the rear diff. Can anyone tell me if that sounds plausible? The RWAL sensor is brand new and they say it appears to read normally up to about 20MPH.

They also said that there is a code for an instrument cluster failure. Is there anyplace to get them repaired or someplace to buy one that's not 500 bucks?

Thanks for any suggestions.