Abstract: A tension detector which senses excessive tension deviation in the yarn fed to a tufting machine to operate a loaded plunger. There is a separate plunger for each yarn end with each plunger operating to complete an electric circuit when the plunger is acted upon by a high tension deviation yarn. The electrical circuit consists of a bank of identical resistors connected in series with a known voltage across them to create a linear voltage divider, a switch corresponding to each resistor, each switch being mounted after its resistor in parallel with the remaining resistors and closed by the actuation of a respective one of the plungers. The voltage indicator can be calibrated to display the particular yarn or needle number directly thereon so that the operator may identify the particular troublesome yarn.