I've repaired wiring inside the jacket to the gloves a couple of times. Both times the break was at the arm pit area and I'm guessing the wire flexes there the most due to arm movement. The bending action at the glove end will also cause breaks at the glove end or controller end. I repaired connectors using N size coaxial fittings. They look different from the original ones that have the wiring insulation molded onto them but they are the same barrel size.
To do the repair I used the continuity function of my multi meter to find exactly where the wire conductor broke inside it's insulated cover, then inserted a short splice of new wire or new N coaxial fitting to restore it. I started by checking for continuity from the glove connector end to the controller connection end to see if the negative or positive conductor broke. The wire inside the jacket is probably a dual conductor like lamp cord. The positive conductor is the inner part of the coaxial female fitting, negative is the outside of the male fitting. On the outside of the dual conductor lamp cord the positive conductor will have a tracer the negative conductor won't have - a molded line on the insulation or perhaps a line of color molded into the insulation. If you look closely you will see it. Next I opened the zipper sewn into the inside of the jacket just above the waist in the back. Locate the wiring inside the jacket between the inner and outer cloth layers. Pick a spot in the exposed wiring and using the sharp end of one of the probes, gently pierce the wire's insulation to make contact with the conductor inside. Use the other probe to touch the appropriate metal part of the coaxial fitting. If continuity is good to that point at the lower back hem, take a exacto blade or knife to make a small slit in the inner layer at the bottom of the arm hole into the jacket sleeve, more or less at the arm pit. 1/2" long is plenty. Fish the wiring through the hole and pull out as much wire as you can. By bunching up the back of the jacket and the jacket sleeve you can expose the wire all the way to the strain relief at the forearm/wrist zipper where the glove end comes out and back down to where you previously tested. Test for continuity between the known good point at the bottom waist hem found previously to the arm pit. You will arrow down to the point where the break is then splice it. After you know you have continuity from the controller end to the glove end and the repair is made good, pull the jacket sleeve and jacket back to natural shape and the wiring inside will move back into place. Test the repair by hooking everything up and checking for heat. Close the zipper and you are done.
