Totally check the pins on the plug that feed out to that string. GI that's on like that all the time gets crispy plugs real quick. It'd be J121 or J120. Sadly I can't tell you the exact pin, as there are no fishtales in the shop at the moment. Also check the GI power/ground in, plug J115. Wiggle all these plugs and see if it turns on or off. Worst case scenario, you blew the transistor that controls that GI line. It happens, but crispy plugs happen more often.