Chuck,
Are you sure about those colors? HB may change the colors without notice, but I have never seen pink and blue wires in a transducer cable. The SI and HDsi transducers use to have the same type of cable and the wires have these functions:
Red - Temp
Black - 200/83/50 kHz
Drain wire and foil shield - Ground for temp and 200/83/50 kHz
Orange - Left SI 262/455/800 kHz
Violet - Ground for left SI
Yellow - Right SI 262/455/800 kHz
Brown - Ground for right SI
Orange is twisted with violet and yellow is twisted with brown. All ground wires are joined at a common pin in the connector.
If the black wire is cut the downward 200/83/50 kHz channel is disabled. The effect is no depth info which will make the unit slow down ping rate to almost nothing (one or two pings per second). The image gets distorted with very low resolution. I have tested this and seen the result...
Rickard