My truck was driving fine then the next time i started it the tach didnt work the shift indicator light wasnt on the speedo doesn't work and the trans starts out in 3rd if i manually downshift i have second but no 1st and no 4th but reverse is fine i tested the vss for ohm's and reads about 1400. i would like to know what do these circuits all have in common and how or where to start testing..oh yea engine ground is good..please help me