I have an 05 Pacifica that I bought about a week ago that had 152k miles on it. Today I turned the navigation on and all of a sudden the speedo started reading irraticley, read 10-15 more mph the what I assume I was going. Then to make things stranger the odometer jumped up adding 100k plus miles. Any information to a cause of this obvious electrical issue and any possibile fixes would be greatly appreciated.