Welcome Goprlc to the HDTimeline forum and your first post...yes it sounds like you have a bad connection as the bike pitches forward a bit, moving things around in the wiring harness, frame and fork members. There could also be leakage current short to ground when you hit the brakes because the tail light has wiring under the fender in a metal loom that may have scuffed insulation and wiring again flexes a bit. Of immediate concern is low initial reading...can you measure with a DMM (Digital Multi-Meter)...? If you do not have one, Harbor Freight sells one for under $8...less with 20% coupon.