Cut red wire on yamaha 703 controler and gauge

[bksah2]

Hi All,, hope you can help,, bought a used boat and it has a 1989 200hp yamaha on it with the older style digital gauges and the 703 controls .. i did some wire traceing and found the following ..a heavy round wire harness comeing from the engine into the 703 controler ,comeing out of the controler a flat wire harness with a green yellow black red wire comeing off the controler to the gauges ,,however the red wire has been cut at the controler and cut again up closer by the gauges, then someone ran a hot wire off the switched panel into the cut red wire going into the gauges ..so my question is ,,
what is the purpose of the red wire,,,
any idea why someone would cut it at the controler
and should i take the controler apart and find the other end and reconnect it...
THANKS